[IndispensableDestiny]

I was not aware that "Cmdr." was a naval rank. I'm used to O-5 Commander as "CDR" I know they renamed O-7, Commodore, as Rear Admiral (lower half) or "RDML"

It's the civilian style of abbreviating rank.

Look in various style guides and you'll find it. For example, an Army Lieutenant General is abbreviated LTG in the military and government, but Lt. Gen. in the press.

[Pollster1]

It's the civilian style of abbreviating rank.

I get it. Until a year ago, I abbreviated "POTUS" as "POS" - civilian style.