How do I show or hide membership messages in a Conversation?

When a user is added to or removed from an item a membership message is posted to the Conversation (for example, The Conversation is now accessible to: John Doe). If you'd prefer not to see those messages, you can hide them.

Click More Conversation Options icon, then select Hide Membership Messages or Show Membership Messages. For more information, see How do I show or hide membership messages?