Also known as: クラスチェンジ
A game mechanic found typically in Roleplaying games, sometimes referred to as a Job Change. It involves changing a character's given class to an entirely different one; in many cases, a character's level will revert back to level 1 when changing to a new class, but will also retain stats from their previous class.
In any case, this tag should be used when a post indicates that the characters present have switched from one class to another, usually involving changing their wardrobe to that of an existing class.