For anyone who need some documents on the SWIFT Cover Payments messages. you can find here.

when I Google MT202 Cover Payments. There are many useful articles there. Major banks often publish their MT202 Cover Payment documents. Here the top result searching on 202cov:

http://www.wolfsberg-principles.com/pdf/Joint_Industry_Slides_on_MT_202_COV_(20-05-09).pdf

Details on cover payments (202 COV and 205 COV), can be found in the SWIFT User Handbook, for Category 2 messages:
https://www2.swift.com/uhbonline/books/protected/en_uk/us2m_20100723/index.htm

when I google Google MT202 Cover Payments. There are many useful articles there. Major banks often publish their MT202 Cover Payment documents. Here the top result searching on 202cov:

http://www.wolfsberg-principles.com/pdf/Joint_Industry_Slides_on_MT_202_COV_(20-05-09).pdf