This image depicts a flag of a Flemish municipality or province. These flags have been registered with the register van gemeentewapens van de Vlaamse Heraldische Raad[1].
The flag belongs to the public domain of a city of municipality. Using it for advertising purposes, for example as a brand, is strictly forbidden.
Article 184 of the Belgian criminal law states that abuse of or forging a seal can be punished with imprisonment between three months to three years. Attempting to create a seal of misuse of it, is punished with imprisonment between one month and one year.
Using the seals by private persons, private institutions or associations is only allowed if the council of the municipality or city has officially given permission for this. See e.g. [2].
In view of Flemish legislation this image is seen as being in the public domain, as are reproductions of this flag.