Velocity A23 rims tubeless

I have picked up what look to be fairly old model Velocity A23s laced to Phils.

Has the A23 rim design always been tubeless compatible, or is it a new variation?

If tubeless compatibility is a new variation, what details should I be looking for to assess which ones I’ve got?

do posts #2 and #6 in this thread help?

Yes, thanks rolly. Mine are non-tubeless then, good to know.

Posting here for the record:

The A 23 with the channel (made in USA ones) are tubeless

I think the ones you bought off me are tubeless…

Yes, I (regrettably) sold those with my stainless SS, and these are different ones again. The cycle continues.