2.2.4.27 SMB_COM_WRITE_MPX_SECONDARY (0x1F)
This command was introduced in the LAN Manager 1.0 dialect (see [SMB-LM1X] section 9.2.22). It was rendered obsolete in the NT LAN Manager dialect.
This command is no longer used in conjunction with the SMB_COM_WRITE_MPX (section 2.2.4.26) command. Clients SHOULD NOT send requests using this command code, and servers receiving requests with this command code SHOULD return STATUS_NOT_IMPLEMENTED (ERRDOS/ERRbadfunc).<37>