This command was introduced in the LAN Manager 1.0 dialect. This command code was designated as the AndX Chain terminator.

Clients SHOULD NOT use this command code in a primary command. Servers receiving this command code in a primary command MUST return STATUS_SMB_BAD_COMMAND (ERRSRV/ERRbadcmd).

In the earliest SMB Protocol specifications (see [IBM-SMB]), this command code was reserved for proprietary protocol extensions. That usage is obsolete. Core Protocol documentation from Microsoft, including [SMB-CORE] and [MSFT-XEXTNP], does not include any reference to the use of this command code for protocol extensions or any other purpose.