I have collected all the changes I noticed in the spreadsheet below, including changes where only a space or a hyphen was inserted or removed between parts of the name. Those spellings which I consider clearly wrong - like Bangkok Noi once spelled Bangkok Koi - are marked in red.
Not surprisingly most of the changes are those due to changes in RTGS. And since some Thai words are found in several district names, the table is somewhat repetitive. The ones which are found several times are the following:
- Mueang (เมือง), previously Muang, meaning "city"
- Bueng (บึง), previously Bung, meaning "swamp"
- Phueng (ผึ้ง), previously Phung, meaning "bee"
- Ruea (เรือ), previously Rua, meaning "boat"