Matching documentation updates (#285)

* Update notes-on-media.md

* Update media-matching.md

documentation/contributing/notes-on-media.md

@@ -1,24 +1,26 @@
 ---
-title: Notes on Media
+title: Notes on Media & Links
 description: Community Notes on posts that contain images or videos
 navWeight: 110
 ---
-# Notes on Media
+# Notes on Media & Links
 
-Community Notes are frequently added to posts that feature images or videos. In many cases, these notes can provide valuable context, not just for a single post, but for any post containing the same media.
+Community Notes are frequently added to posts that feature images, videos or links. In many cases, these notes can provide valuable context, not just for a single post, but for any post containing the same media.
 
-Contributors with a [Writing Impact score of 2 or above](../under-the-hood/media-matching.md) have the option to write notes about the media found within posts, as opposed to focusing on the specific post. Contributors should select this option when they believe the context added would be helpful independently of the post the note is attached to.
+Contributors with a [Writing Impact score of 2 or above](../under-the-hood/media-matching.md) have the option to write notes about the media found within posts, as opposed to focusing on the specific post. Contributors with a Writing Impact score of 10 or above also have the option to write notes about links found within posts.
 
-![Note-writing form with option: Is your note about the post or the image?](../images/notes-on-media-01.png)
+Contributors can select one of these options when they believe the context added would be helpful independent of the post the note is attached to.
 
-Tagging notes as “about the image” (or video) makes them visible on all posts that our system identifies as containing the same media. These notes, when deemed Helpful, accumulate view counts from all the posts they appear in, but only count as one Writing and Rating Impact for the author and raters.
+![Note-writing form with option: Is your note about the post, the image/videdo, or the link?](../images/notes-on-media-01.png)
+
+Tagging notes as “about the image” (or video, or link) makes them visible on all posts that our system identifies as containing a matching image, video or link. These notes, when deemed Helpful, accumulate view counts from all the posts they appear in, but only count as one Writing and Rating Impact for the author and raters.
 
 ![Multiple posts with same image and the same note applied](../images/notes-on-media-02.png)
 
-To ensure transparency, raters will see a disclaimer indicating that notes about the image may appear across multiple posts. This way, they'll be aware that the context provided by these notes extends beyond the specific post they're currently viewing.
+To ensure transparency, raters will see a disclaimer indicating that notes about the media may appear across multiple posts. This way, they'll be aware that the context provided by these notes extends beyond the specific post they're currently viewing.
 
 When someone rates a media note, the rating is associated with the post on which the note appeared. This allows Community Notes to identify cases where a note may not apply to a specific post.
 
 ![Rating screen with callout: This note is about the image and could be shown on all posts that contain the same image](../images/notes-on-media-03.png)
 
-Currently, this feature supports posts with a single image or single video. We may expand it to cover multiple media and new media types.
+Currently, this feature supports posts with a single image or single video, or a link. We may expand it to cover posts that contain multiple media.

documentation/under-the-hood/media-matching.md

@@ -5,15 +5,15 @@ navWeight: 30
 ---
 # Media Matching
 
-Contributors can write [notes on media](../contributing/notes-on-media.md) (images and videos) that show on posts that contain matching media. 
+Contributors can write [notes on media](../contributing/notes-on-media.md) (images, videos and links) that show on posts that contain matching media. 
 
 ### Earning the ability to write notes on media
 Contributors can write notes on media if they have sufficient [Writing Impact](../contributing/writing-and-rating-impact.md):
-* Contributors with 2+ Writing Impact can write notes on media, and their notes get associated with other posts with matching media if there is sufficient agreement from raters that the note will be helpful on all posts with matching media
-* Contributors with 10+ Writing Impact can write notes on media, and their notes are automatically associated with other posts with matching media
+* Contributors with 2+ Writing Impact can write notes on images and videos (though not links), and their notes get associated with other posts with matching media if there is sufficient agreement from raters that the note will be helpful on all posts with matching media
+* Contributors with 10+ Writing Impact can write notes on images, videos and links, and their notes are automatically associated with other posts with matching media
 
 ### Determining sufficient agreement to match a note to other posts
-To be shown to everyone on X, notes need to reach a status of Helpful. Additionally, media notes may need further agreement that the note will be helpful on all posts that contain matching media. This helps prevent cases where a note is specific to a given post, but ends up matching to many other irrelevant posts with the same media, simply because the note auther wrote it as a media note. 
+To be shown to everyone on X, notes need to reach a status of Helpful. Additionally, media notes may need further agreement that the note will be helpful on all posts that contain matching media. This helps prevent cases where a note is specific to a given post, but ends up matching to many other irrelevant posts with the same media, simply because the note author wrote it as a media note. 
 
 When rating a media note, contributors answer this additional question:
 
@@ -24,3 +24,13 @@ Currently, sufficient agreement is defined as:
 * 80%+ of raters from each factor sign agree the note will be helpful if shown on all posts with matching media
 
 The rater factor used in the calculation is the factor from the [model that determined the note's status](./ranking-notes.md) (e.g. CoreModel, GroupModel01, etc)
+
+### Link matching
+Notes on links are new. Some details on how link matching works in this initial experimental phase:
+* Links can have many variations — URL shortened (ex.co/a1b2), URL parameters (?source=shareLink), etc. Link matching aims to match on the ultimate URL to which the link resolves, ignoring unnecessary URL parameters.
+* Notes are not currently allowed on base domains (like example.com)
+* Notes that are not rated Helpful within two weeks will stop matching to new posts.
+
+We will be listening to contributor feedback and may adjust these details.
+
+