Some desks have the form of a table, although usually only one side of a desk is suitable to sit at (there are some exceptions, such as a partners desk),[3] unlike most usual tables. Some desks do not have the form of a table, for instance, an armoire desk[4] is a desk built within a large wardrobe-like cabinet, and a portable desk[5] is light enough to be placed on a person's lap. Since many people lean on a desk while using it, a desk must be sturdy.