My wife recently decided to sort out various land ownership conflicts, coming from the fact that the land we live on was divided up between family members at the time of her father's death. We needed a lawyer for this, even though there is no contesting our intentions. He told us that it would be better if I got a yellow house book (Tabien baan), for reasons that still remain obscure to us.
The general consensus amongst ex-pats seems to be that it isn't necessary. However we found that the local Amphur were very enthusiastic about me going forward with obtaining the book and when we finally got the book two senior officials appeared and a group foto was taken. "Welcome to Thailand" was written on a prepared sign behind us ... I've been here for 11 years. . anyway, I guess I will no longer need a residence certificate every time I buy a house, renew my driving licence or open a new bank account. It wasn't an easy process and mostly our fault, the visit to Chaeng Wattana was most frustrating and in the end unnecessary, also with hotel, travel, embassy and translation services kind of expensive.
It is still a mystery to me why I need this book.