I got the 30 day 'under consideration' stamp - they didn't ask for the missing document (my latest income tax return) so I didn't mention it. Not sure if that was the correct thing to do or not!
Balls. I already have my work permit but am missing a document needed for my 1 year extension. Apparently there's no time to get this before my type B expires. If I go and get a new type B is my work permit still good or will that be affected as well?
I think it's just the additional sticker that they put in non-chipped passports. They remove half on departure, and leave behind the bit you see here. Not sure why Thai immigration wouldn't be used to this.