The SID structure is a variable-length structure used to uniquely identify users or groups. SID stands for security identifier. Applications are not to modify the SID structure directly. To create and manipulate a security identifier, use the functions listed in the See Also section. typedef PVOID PSID; See Also AllocateAndInitializeSid, CopySid, EqualSid, FreeSid, GetLengthSid, GetSidIdentifierAuthority, GetSidLengthRequired, GetSidSubAuthority, GetSidSubAuthorityCount, InitializeSid, IsValidSid, LookupAccountName, LookupAccountSid Winfried