Last minute before I leave I noticed this new announcement in the Royal Gazette. At first look it seemed to be the rename of a subdistrict (tambon) in Sawang Daen Din district, Sakon Nakhon province, as its title says "เปลี่ยนแปลงแก้ไขชื่อตำบล" (change to correct name of subdistrict). And even my tool to find such new announcements assigned it into this category.
But in fact it is not the subdistrict itself which is renamed, but the constituency, which was previously named “ตำบลดอนเขือง” (Don Khueang subdistrict), as it only covered the subdistrict municipality Don Khueang (เทศบาลตำบลดอนเขือง). But in February 2005 the boundaries of the constituency were changed and it now covers non-municipal parts of the subdistrict Waeng as well - the municipality Don Chiang is a former sanitary district (sukhaphiban) which covers only the central part of the subdistrict. So in fact only the constituency (เขตเลือกตั้ง) was renamed to “ตำบลแวง” (Waeng subdistrict).