Prescription level - glossary entry

[Stephen Green <stephen.green@documentengineeringservices.com>]

As discussed in last meeting, I propose adding a little
to the prescription level entry in the glossary to cover
distinct shades of meaning (e.g. RFC or ISO/IEC
normative language distinctions):

We have so far:
"The test assertion defines a normative statement which
may be mandatory (MUST/REQUIRED), permitted
(MAY/OPTIONAL) or preferred (SHOULD/RECOMMENDED).
This property can be termed the test assertion’s prescription
level. NOTE: in the case of the normative source including
keywords 'MUST NOT' the prescription level 'mandatory' is
used and the 'NOT' included in the predicate."

I propose to add:
"There are differences between various conventions of
normative language and the above terms may be extended
with more specialized terms for a particular convention and
its distinct shades of meaning."

Anyone offer any alternatives?
---
Stephen D Green