Civil Service Flag of Siam according to the Flag Regulations for the Kingdom of Siam Rattanakosin Era 110.
No. 7.Civil Service Flag.

This flag is also the same as the Diplomatic Service Flag, except that in the upper right hand corner, instead of the scutcheon and Arms etc., is a plain white field of circular shape, the diameter of which is equal to one forth of the breadth of the flag. On this white field is shown the seal of office used by Governors of Provinces in their district.
Own work
Sodacan