sn.exe exit code documentation ?

Hi,

When one calls sn.exe, what are the expected error codes (errorlevel) in return ?

I'm using delay signing. I think about three cases when achieving the final signing:
- assembly was signed successfully (seems to be errorlevel 0)
- assembly was not signed because it's already signed with the provided key
- assembly could not be signed (either because it's already signed with another key, or file not found etc)

I could not find anything related to those exit codes in the documentation. Is there any official reference for that ?

kind regards

Thibaut Barrère