drive. This is a great way to reach a lot of people!
1. Please review the Operations Working Group's [Banner Policy](https://operations.osmfoundation.org/policies/banner/) to know whether your event qualifies for a front-page banner.
-2. Create the banner image. Some guidelines:
- * Image should be 350px wide (exactly) x 350px tall (or shorter).
- * Use a standard web image format (.gif, .jpg, .png)
- * Note that a close 'X' button will be drawn over the top right 60x60px corner of the banner, so please do not put anything important in that space.
+2. Create the banner image. The image needs to:
+ * be exactly 350px wide and at most 350px tall,
+ * be in PNG format,
+ * have nothing important in the top-right 60x60px corner of the banner which has a close 'X' button overlayed, and
+ * have sufficient visual contrast with the colours #cccccc and #999999 so the 'X' can be seen.
3. Prepare a pull request which includes the following:
* The banner should be saved under the [`app/assets/images/banners/`](https://github.com/openstreetmap/openstreetmap-website/tree/master/app/assets/images/banners) folder, and should have a name that makes it clear what it is for (e.g. `donate-2017.jpg`)
* Edit [`config/banners.yml`](https://github.com/openstreetmap/openstreetmap-website/blob/master/config/banners.yml) to contain an entry for the event banner. It should contain the following:
* `img` - the filename for the banner image (e.g. `banners/donate-2017.jpg`)
* `enddate` - the final date that the banner will be shown (e.g. `2017-oct-31`)
* (optional) Feel free to cleanup the old images from the `app/assets/images/banners/` folder and old entries in the `config/banners.yml` file.
+4. The pull request must indicate when the banner should start being shown, which must be at least 7 days after the pull request was created.
See [PR #1296](https://github.com/openstreetmap/openstreetmap-website/pull/1296)
as an example.