From N Gauge wiki
SMF (forum software) allows members to customise their own profile on the forum. The standard profile allows a members to add a picture/avatar to represent their image on the forum. Members are also able to add their birthday, a website address, social networking details, a signature, gender and Country where they reside. All of which is optional.
Ultimate Profile - Modification
Members are able to activate a modification to the standard forum profile which changes the style to Ultimate Profile (UP). This allows the page to be customised and can include more interesting features.
Some extra features that are allowed with 'UP' are:- A header image, multiple profile pictures, Youtube video's, comments (from other members), Classifieds Feedback, plus more.