Part 4—Other requests by ICC
Division 2—Documentation to accompany request
50 Documentation for request
(1) A request for cooperation (other than a request to which subsection (2) applies) must, as applicable, contain or be supported by:
(a) a concise statement of the purpose of the request and the assistance requested, including the legal basis and the grounds for the request; and
Statement of purpose of request and assistance sought
EDIT.