One has to wonder why they are different, unless the Amphur in Udon Thani's Nong Saeng district had that removed as it does not really apply in our cases.
Different provinces and Amphurs with there own sets of rules and regulations as we continually see.
The entire back of my wifes is just her work permit, nothing saying she must get permission to leave the area as it lists her job as a housekeeper/nanny. Must be because she is allowed to travel with her employer, which ironically is me.