I've seen it used somewhat often in the UK (almost entirely in academia as far as I can recall), at least frequently enough that I've used it in my own writings despite not studying history.

At a quick search, I can find a couple of sources that suggest it for notetaking at least:

* University of Portsmouth (listed under "Common general abbreviations") https://www.port.ac.uk/student-life/help-and-advice/study-sk...

* University of South Australia (under "Common symbols and abbreviations") https://lo.unisa.edu.au/pluginfile.php/1687781/mod_resource/...