Limited users are prevented from accessing several features on Steam, including but not limited to:
◾Sending friend invites
◾Opening group chat
◾Voting on Greenlight, Steam Reviews and Workshop items
◾Participating in the Steam Market
◾Posting frequently in the Steam Discussions
◾Gaining Steam Profile Levels (Locked to level 0) and Trading Cards
◾Submitting content on the Steam Workshop
◾Posting in an item's Steam Workshop Discussions
◾Accessing the Steam Web API
◾Using browser and mobile chat
◾Adding public artwork and screenshots