Document which id fields to use for Mobileclient.add_songs_to_playlist [Closes
@@ -621,6 +621,8 @@ class Mobileclient(_Base):
:param playlist_id: the id of the playlist to add to.
:param song_ids: a list of song ids, or a single song id.
+ These can be ``'storeId'`` from a store song, ``'id'`` from an uploaded song, or
+ ``'trackId'`` from a playlist entry.
Playlists have a maximum size of 1000 songs.
Calls may fail before that point (presumably) due to
