Some more details

radiantearth · Apr 23, 2021 · 59df72d · 59df72d
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Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/best-practices.md b/best-practices.md
@@ -45,6 +45,7 @@
     - [Keep catalogs in sync with cloud notification and queue services](#keep-catalogs-in-sync-with-cloud-notification-and-queue-services)
   - [How to Differentiate STAC Files](#how-to-differentiate-stac-files)
 
+
 This document makes a number of recommendations for creating real world SpatioTemporal Asset Catalogs. None of them 
 are required to meet the core specification, but following these practices will make life easier for client tooling
 and for users. They come about from practical experience of implementors and introduce a bit more 'constraint' for
@@ -293,7 +294,7 @@ following table lists some of the most common ones you may encounter or use.
 | `image/png`                                             | Visual PNGs (e.g. thumbnails)                                |
 | `image/jpeg`                                            | Visual JPEGs (e.g. thumbnails, oblique)                      |
 | `text/xml` or `application/xml`                         | XML metadata [RFC 7303](https://www.ietf.org/rfc/rfc7303.txt) |
-| `application/json`                                      | A JSON file (often metadata, or [labels](https://github.com/radiantearth/stac-spec/tree/master/extensions/label#labels-required)) |                   
+| `application/json`                                      | A JSON file (often metadata, or [labels](https://github.com/radiantearth/stac-spec/tree/master/extensions/label#labels-required)) |
 | `text/plain`                                            | Plain text (often metadata)                                  |
 | `application/geo+json`                                  | [GeoJSON](https://geojson.org/)                              |
 | `application/geopackage+sqlite3`                        | [GeoPackage](https://www.geopackage.org/)                    |
@@ -634,7 +635,7 @@ a number of the common official relations that are used in production STAC imple
 | via       | The URL of the source metadata that this STAC Item or Collection is created from. Used similarly to canonical, but refers back to a non-STAC record (Landsat MTL, Sentinel tileInfo.json, etc) |
 | prev      | Indicates that the link's context is a part of a series, and that the previous in the series is the link target. Typically used in STAC by API's, to return smaller groups of Items or Catalogs. |
 | next      | Indicates that the link's context is a part of a series, and that the next in the series is the link target. Typically used in STAC by API's, to return smaller groups of Items or Catalogs. |
-| preview   | This link relation can be used to "refer to a resource that serves as a preview of the link's context, likely with reduced quality or limited content" (from [rfc6903](https://tools.ietf.org/html/rfc6903#section-3)). For geospatial information this is generally a thumbnail, and in STAC this would usually be the same href as the [thumbnail](#thumbnail) asset, to enable more general clients to make use of it. |
+| preview   | Refers to a resource that serves as a preview (see [RFC 6903, sec. 3](https://tools.ietf.org/html/rfc6903#section-3)), usually a lower resolution thumbnail. In STAC this would usually be the same URL as the [thumbnail](#thumbnail) asset, but adding it as a link in addition enables OGC API clients that can't read assets to make use of it. It also adds support for thumbnails to STAC Catalogs as they can't list assets. |
 
 ### Versioning for Catalogs