This function enables the type provider to determine whether two different user strings are semantically equivalent.
DWORD MatchUser( DWORD dwType, PWSTR wszSrc, PWSTR wszDest, DWORD dwFlag, PBOOL pbMatch );
ERROR_SUCCESS is returned upon success. For a list of error codes, see Credential Manager Error Codes.
If the credential type provider does not implement MatchUser, then a case insensitive comparison is done by credential manager to compute the equivalency. Thus, even though
user@domain may be the same user, MatchUser will return an error if the credential type provider does not implement it.