[Pals] Alvaro Retana's No Objection on draft-ietf-pals-ethernet-cw-06: (with COMMENT)

Alvaro Retana has entered the following ballot position for
draft-ietf-pals-ethernet-cw-06: No Objection

When responding, please keep the subject line intact and reply to all
email addresses included in the To and CC lines. (Feel free to cut this
introductory paragraph, however.)


Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
for more information about IESG DISCUSS and COMMENT positions.


The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-pals-ethernet-cw/



----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

The title of the document is "Use of Ethernet Control Word RECOMMENDED", which
hints at the corresponding rfc2119 keyword:

   3. SHOULD   This word, or the adjective "RECOMMENDED", mean that there
      may exist valid reasons in particular circumstances to ignore a
      particular item, but the full implications must be understood and
      carefully weighed before choosing a different course.

That seems to be in line with the description in the Introduction: "This
document recommends the use of the Ethernet pseudowire control word in all but
exceptional circumstances."

However, the qualified recommendation is that if "both the ingress PE and the
egress PE support the Ethernet pseudowire control word, then the CW MUST be
used".  What are the "exceptional circumstances"?  Should that "MUST" be a
"SHOULD"?  Should the use be further qualified?

This comment is not a showstopper, just a minor misalignment.