diff --git a/docs/specs/playlist-library-federation/index.md b/docs/specs/playlist-library-federation/index.md
index bf91e3887..33bc736d8 100644
--- a/docs/specs/playlist-library-federation/index.md
+++ b/docs/specs/playlist-library-federation/index.md
@@ -21,6 +21,11 @@ Users will be able to click on a "Request access to playlist audios files" butto
 `Upload` many_to_one with `Library` through `library` (reverse is `library.uploads`)
 `Upload` has also a many_to_many with `Library` through `playlist_libraries` (the same upload can be share various time in through various playlists). Reverse relation is `library.playlist_uploads`
 
+##### Federation
+
+Since `Playlist` is the main object here, we use the `Playlist` activities to send the `Library` information on ActivitiPub.
+There is no other reason to share the playlit.library to remote.
+
 ##### Migrations
 
 1. Remote library are not changed