EDIT since Stentor posted while I was.
Kewl IPT and Stentor ...
I don't know if I can get as close up as IPT's with this old P&S, but gonna try I guess.
#9 has them inside and out, but mostly concentrated in the interior bottom. They look like they were bubbles that "popped" and then filled in with translucent glaze. I have to get a magnifyer out and check it out.
Aging will be a curious thing.
Hmm, I usually rinse with very hot water after using, then pat dry and set out in open air. This one might call for turning upside down ...
Going to use it shortly.