Every distinct wording since 2010, newest first.
April 14, 2023 · March of the Machine
The text box of a Class card contains class level bars, each of which is a keyword ability that represents both an activated ability and a static ability. A class level bar includes the activation cost of its activated ability and a level number. Any abilities printed within the same text box section as the class level bar are part of its static ability. See rule 716, “Class Cards.”
July 23, 2021 · Adventures in the Forgotten Realms
The text box of a Class card contains class level bars, each of which is a keyword ability that represents both an activated ability and a static ability. A class level bar includes the activation cost of its activated ability and a level number. Any abilities printed within the same text box section as the class level bar are part of its static ability. See rule 717, “Class Cards.”