irregular gameplay

how does one play irregular?

i got that message some days ago and its just now that im wondering how i played irregular.
i love playing scout with 2 flash, a nade and a smoke but most of the time i only buy scout, 1 flash and 1 nade.

im wondering if its what i buy that makes me play irregular or if its just becaus of how i play in general.

anyone who might have theories or who knows what valve sees as irregular since those 20 hour bans are annoying.