This last weekend I was informed of the process for obtaining a "Non-Quota Immigration Visa" by submitting a TM22 form to Bangkok Immigration. I've lived in Thailand for 23 years now and never come across this type of visa before. Google has not been my friend so does anyone know of this type of visa and why one should need one?

That visa is only issued to those who have permanent residency in Thailand.

If you sit on a Permanent Residence Status (lifelong stay permit without 90-days, yearly re-application, minimum fund etc.) then you have to get a TM22 which will allow you to leave the country on a re-entry basis. Beware thought, that this TM22 is valid only for one year; should you stay outside Thailand after the expiry date of TM22, then you will lose the PR. 

Attached hereto I send you the respective form TM22 for your perusal; good luck! 

TM 22 BLANK.doc