I am now completely confused with the numerical codes for the Chumchon (ชุมชน, best translation might be "borough"), the subdivisions of the municipalities. Some time ago, I found that in Ang Thong the codes follow a simple rule, using the municipality code as the basis and then adding 00xx. Except that there's of course the problem with the lack of codes for all the municipalities, this makes perfect sense as the Chumchon are at a similar administrative level as the villages, which has a similar coding scheme.
However, now I took a look at the website of Warin Chamrap town, adjoining to the south of Ubon Ratchathani city. The page which shows the map of the town, including the full boundaries of all the Chumchon, also includes a list with the names and codes (รหัสชุมชน) of all 28 subdivisions. To my surprise, the codes there are from 34150101 to 34150128, which would be normally the code range for administrative villages (Muban) in Warin Chamrap subdistrict. Since this subdistrict is completely covered by the town municipality (it was upgraded to a town in 1995), it has no Muban anymore, so these codes are free. But nevertheless, I would have expected the codes to be 34980001 to 34980028 instead.
The pages on the Warin Chamrap website all have the possibility to add comments, so I tried my luck and posted this question there as well - though I have not much hope I will get any answer.