User blog comment:Kyran Kandosa2/An PSA on Berserks and other "Rage Mode" Semblances, Part 1: The basics/@comment-17970636-20140715045955

Yang doesn't appear to follow this terminology whatsoever, so, case in point, this may actually be obsolete within RWBYverse. Her trigger is her hair, for the most part, although we have seen it surface when she is annoyed, and she does keep her state of mind when in this mode. So, there's that.