Here are my comments:
The IANA Considerations section needs to be revised. It is recommended that the IANA considerations section be rewritten
according to the recommendations of RFC 5226, and that this be cited as a
normative reference.
Some issues:
1. The IANA considerations section does not specify how attributes are to be allocated from the extended space, using policy terms defined in RFC 5226.
2. Normative language terms "SHOULD"/"SHOULD NOT" are used in Sections 9.1 and 9.5.
The IANA is not a policy making body and therefore is not capable of handling MAY, SHOULD or SHOULD NOT directives.
9.1. Attribute Allocations
IANA is requested to move the "Unassigned" numbers in the range
144-191 from "Unassigned" to "Deprecated". This status means that
allocations SHOULD NOT be made from this space. Instead, allocations
SHOULD be taken from the Extended Type space, starting with lower
numbered attributes. However, allocation from the "Deprecated" space
MAY still be performed by publication of an IETF specification, where
that specification requests allocation from the "Deprecated" space,
and gives reasons why use of the Extended Type space is impossible.
[BA]
It seems that the goal is to still allow allocation from the Unassigned range, while preferring allocation from the Extended Type space.
A more implementable way of accomplishing this might be to say that unless specifically requested to allocate from the Standard RADIUS space,
IANA should make allocations from the extended type space.
9.5. Extending the RADIUS Attribute Type Space
The extended RADIUS Attribute Type space may eventually approach
exhaustion. When necessary, the space SHOULD be extended by
publication of a specification which allocates new attributes of
either the "Extended Type", or the "Extended Type with flags" format.
[BA] This material relates to IETF not IANA processing, and so is not
appropriate for an IANA considerations section. The IANA cannot handle
the policy decisions that are implied here.
The specification SHOULD request allocation of a specific number from
the "Reserved" RADIUS Attribute type space, such as 247. The
attribute(s) SHOULD be given a name which follows the naming
convention used in this document. The Extended-Type value of 26 MUST
be allocated to a "Vendor Specific" attribute, of data type "esv".
The Extended-Type values of 241 through 255 MUST be marked as
"Reserved".
IANA SHOULD allocate the attribute(s) as requested. For example, if
allocation of attribute 247 is requested, the following definitions
MUST be made in the specification, and allocated by IANA.
* 247.1 Extended-Attribute-7
* 247.{1-25} Unassigned
* 247.26 Extended-Vendor-Specific-7
* 247.{27-240} Unassigned
* 247.{241-255} Reserved
We note,however, that the above list is an example, and we do not
request or perform allocation of attribute 247 in this document.