document owner permission

[thefoolcoder]

Hi to all,
when I create a new document, problem or risk for a certain project,
project server suggests me only some resouce (e.g res1 and res2) which
can be the document (problem or risk) owner, but I can't understrand
what particular authorization res1 and res2 have to be a document
owner.
Can anybody suggest me which authorization I should set for a resouce
res3 so that when I will create a new document I will able to assign it
to res3?
Any suggestion will be valued!!
Gabriele