Avatars have access to the "IsOnFriendsList" parameter, to tell if a player is on the friends list of the one wearing the avatar. Having access to this boolean value via a method on a VRCPlayerApi object would be a useful feature for world creators to utilize. Some examples might include: limiting player teleporting to people you're friends with, showing indicators for friends in a room, default sharing permissions for certain features to be open to friends, prioritizing grouping friends on teams in game worlds, etc.