What are the multi-entry rules for the Non-O visa in Thailand based on marriage?

Could you list the docs you needed or pm me a list. I plan on going here before end of year for same Visa. Also did your spouse write the letter or is there a generic version somewhere online?

Yep, you can exit/re-enter as many times as you want during the year the visa is valid for and every entry will get you stamped in for 90 days

You can get 15 months of stay (in 90 day increments) out of that visa AND you can extend the last 90 day entry by 60 days under the 'visit family' clause for 1900baht at the immigration office to actually take your total time to 17 months.

In fact most offices let you extend ANY of those 90 day entry stamps another 60 days under that clause. BUT check with them, a few will only let you do a 60 day extension ONCE per VISA, not once per entry.

yes I did that, what I am not sure is if on the last 90 day one you can extend by 60 days at IO to stretch it to 17 months?

it sounds correct to me