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This document specifies the new IANA registry for the first Nibble Following a Label Stack. In addition, this document provide requirements for registering new values and recommendation for MPLS packet processing.
This document is well written and is on the right track, however, I do have a few comments for questions and clarifications:

1. Abstract
Abstract said:
“this memo sets out some documentation requirements for registering new values. Finally, it provides some recommendations that make processing MPLS packets easier and more robust.”

Abstract also said:
“This document updates RFC 4928 by deprecating the heuristic method for identifying the type of packet encapsulated in MPLS.”

I am wondering whether deprecating the heuristic method for identifying the type of packet encapsulated in MPLS is seen as recommendation or requirements, if yes, is such duplicated?

2. Abstract
Some place in the abstract uses the term "This memo", some place in the place uses the term "this document", the same comment is applied to the introduction section, suggest to make these terms consistent? Suggest to use the term "This document".

3. Section 1
Introduction said:
“
This memo introduces a requirement and a recommendation. The first builds on Section 2.1.1, and the second deprecates the use of the heuristic in Section 2.1.1.1 and recommends using a dedicated label value for load balancing.
”

Abstract also said:
“
this memo sets out some documentation requirements for registering new values. Finally, it provides some recommendations that make processing MPLS packets easier and more robust.
”

How many requirements and recommendations are specified by this document, one or many, it looks the abstract is not consist with Introduction for this.
Secondly, where these requirements and recommendations are documented? Only section 2.1.1 and section 2.1.1.1, or we have some other sections?
My suggestion is to have two clear sections to document requirements and recommendations separately.

4. Section 3.1
Section 3.1 said:
“
The assignment policy for the registry is Standards Action.
“
Can we add reference for standard action, I think it should be RFC8126.