iSCSI: iSCSI untagged task and SAM-2 SIMPLE task?

[Luben Tuikov <luben@splentec.com>]

What is the iSCSI ``Untagged'' task (9.3.1)?

SAM-2, 4.9.1 The Task Object, says:

`` An untagged task is represented by an I_T_L nexus
  (see 4.10) and is composed of a definition of the work
  to be performed by the logical unit, and implicitly
  a SIMPLE task attribute (see 7.5).''

and

`` Also, an untagged task is assumed to have a SIMPLE task
  attribute, leaving the initiator no control over its
  relationship to other tasks in the task set.''

So, what is the iSCSI ``Untagged'' task?
Shouldn't that be a SIMPLE task? And get rid of
the ``Untagged'' task?

Also SAM-2, 4.9.2 Task Tags says:

`` A tag is a field containing up to 64 bits that is a
   component of an I_T_L_Q nexus. An initiator assigns
   tag values in each I_T_L_Q nexus in a way that ensures
   that the nexus uniqueness requirements stated in 4.9.1
   are met.''

If the initiator assigns task tags in an I_T_L_Q nexus,
how are they known to the target in terms of iSCSI?

-- 
Luben