Sorry, I should elaborate on documentation.
I provided the completed application form, TM30 print out, and copy of passport biodata page, visa page (I have a Thai Elite Visa, others may not have a visa) and passport page showing latest entry stamp. All pages signed by me in blue ink as requested by the IO. Handed over 200 ฿ to IO and was given a Thai Post reference number and told to expect CoR in post in one week. That was it!!!