X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/4ff0e20e1f1f44cb2d4385f1ebc5bac4aa6aff11..2c909c1f0c7c6e6a176eb5cc15e8d6a45449ebe8:/docs/develop/Ranking.md?ds=inline diff --git a/docs/develop/Ranking.md b/docs/develop/Ranking.md index 278039db..5b1ca191 100644 --- a/docs/develop/Ranking.md +++ b/docs/develop/Ranking.md @@ -7,7 +7,7 @@ different purposes, which are explained in this chapter. ## Search rank The search rank describes the extent and importance of a place. It is used -when ranking search result. Simply put, if there are two results for a +when ranking search results. Simply put, if there are two results for a search query which are otherwise equal, then the result with the _lower_ search rank will be appear higher in the result list. @@ -23,7 +23,7 @@ rank | typical place types | extent 4 | countries | - 5-9 | states, regions, provinces | - 10-12 | counties | - -13-16 | cities, municipalities, islands | 7.5 km +13-16 | cities, municipalities, islands | 15 km 17-18 | towns, boroughs | 4 km 19 | villages, suburbs | 2 km 20 | hamlets, farms, neighbourhoods | 1 km @@ -51,16 +51,24 @@ The following table gives an overview how ranks are mapped to address parts: 10-12 | county 13-16 | city 17-21 | suburb - 22-25 | neighbourhood + 22-24 | neighbourhood + 25 | squares, farms, localities 26-27 | street 28-30 | POI/house number The country rank 4 usually doesn't show up in the address parts of an object. The country is determined indirectly from the country code. -Ranks 5-25 can be assigned more or less freely. They make up the major part +Ranks 5-24 can be assigned more or less freely. They make up the major part of the address. +Rank 25 is also an addressing rank but it is special because while it can be +the parent to a POI with an addr:place of the same name, it cannot be a parent +to streets. Use it for place features that are technically on the same level +as a street (e.g. squares, city blocks) or for places that should not normally +appear in an address unless explicitly tagged so (e.g place=locality which +should be uninhabited and as such not addressable). + The street ranks 26 and 27 are handled slightly differently. Only one object from these ranks shows up in an address. @@ -79,9 +87,9 @@ into the database. There are a few hard-coded rules for the assignment: * highway nodes * landuse that is not an area -Other than that, the ranks can be freely assigned via the JSON file -defined with `CONST_Address_Level_Config` according to their type and -the country they are in. +Other than that, the ranks can be freely assigned via the JSON file according +to their type and the country they are in. The name of the config file to be +used can be changed with the setting `NOMINATIM_ADDRESS_LEVEL_CONFIG`. The address level configuration must consist of an array of configuration entries, each containing a tag definition and an optional country array: