X-Git-Url: https://git.openstreetmap.org./chef.git/blobdiff_plain/dc523913e3d6561d8dcb64e85508b30919d31c9b..ec391f0f0c548939d65966446dc815f5f5a51ba6:/cookbooks/imagery/recipes/gb_os_sv.rb?ds=sidebyside

diff --git a/cookbooks/imagery/recipes/gb_os_sv.rb b/cookbooks/imagery/recipes/gb_os_sv.rb
index 1a61313ac..6dd2e9861 100644
--- a/cookbooks/imagery/recipes/gb_os_sv.rb
+++ b/cookbooks/imagery/recipes/gb_os_sv.rb
@@ -43,7 +43,7 @@ end
 
 imagery_site "os.openstreetmap.org" do
   title "OpenStreetMap - Ordnance Survey OpenData - Street View"
-  aliases ["os.openstreetmap.org", "a.os.openstreetmap.org", "b.os.openstreetmap.org", "c.os.openstreetmap.org", "os.openstreetmap.org.uk", "a.os.openstreetmap.org.uk", "b.os.openstreetmap.org.uk", "c.os.openstreetmap.org.uk"]
+  aliases ["os.osm.org", "os.openstreetmap.org.uk"]
   bbox [[49.85, -10.5], [58.75, 1.9]]
 end
 
@@ -191,86 +191,88 @@ imagery_layer "gb_os_sv_2016_04" do
   url_aliases ["/sv-2016-04", "/sv"] # Add "/sv" to current edition for backward compatibility
 end
 
-# Diff layers
+# ======= Diff layers =======
+
 imagery_layer "gb_os_sv_diff_2010_04_2010_11" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2010"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2010-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2010-11"]
   overlay true
-  revision 2
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2011_05" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2011"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2011-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2011-05"]
   overlay true
-  revision 2
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2011_11" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2011"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2011-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2011-11"]
   overlay true
-  revision 2
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2012_05" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2012"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2012-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2012-05"]
   overlay true
-  revision 2
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2012_11" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2012"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2012-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2012-11"]
   overlay true
-  revision 1
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2013_05" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2013"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2013-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2013-05"]
   overlay true
-  revision 1
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2013_11" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2013"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2013-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
   extension "os_sv_diff_png"
   url_aliases ["/sv-diff-2010-04-2013-11"]
   overlay true
-  revision 1
 end
 
 imagery_layer "gb_os_sv_diff_2010_04_2014_04" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to April 2014"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2014-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
@@ -281,6 +283,7 @@ end
 
 imagery_layer "gb_os_sv_diff_2010_04_2014_10" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to October 2014"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2014-10-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
@@ -291,6 +294,7 @@ end
 
 imagery_layer "gb_os_sv_diff_2010_04_2015_05" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2015"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2015-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
@@ -301,6 +305,7 @@ end
 
 imagery_layer "gb_os_sv_diff_2010_04_2015_11" do
   site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2015"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2015-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
@@ -309,673 +314,740 @@ imagery_layer "gb_os_sv_diff_2010_04_2015_11" do
   overlay true
 end
 
-# imagery_layer "gb_os_sv_diff_2010_04_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2011_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2011-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2011_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2011-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2011_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2011-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2011-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_10_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-10-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_10_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-10-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_10_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-10-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2015_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2015-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2015_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2015-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2015_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2015-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2015-11-2016-04"]
-#   overlay true
-# end
-#
+imagery_layer "gb_os_sv_diff_2010_04_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to April 2016"
+  default_layer true
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2011_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2011-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2011_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2011-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2011_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2011-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2011-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_10_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes October 2014 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-10-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_10_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes October 2014 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-10-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_10_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes October 2014 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-10-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2015_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2015 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2015-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2015_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2015 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2015-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2015_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2015 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2015-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2015-11-2016-04"]
+  overlay true
+end