Authorization for photo rep

[limazita]

Hi,
A graphic designer/publisher friend of mine who is overseas wants to represent me in the country where he is in as he knows magazines who might be interested in publishing my photos or sell my photos. He is someone whom I trust, but we still need to draft some form of authorization to say that he is my rep in that country. I would like to know what should be included in this photo rep authorization and if there is any templates for such authorization/contract online. Thanks!