1. Second sentence says "The enumerations for this version of the protocol are shown...". This reads a bit strangely
a) I would say either "enumeration" or "values", not "enumerations"
b) It's not necessary to say "this version of the protocol"

2. Typo in PUBREC (Etiter)

3. Inconsistent capitalisation of words in the Description column. I favour having capitals only on the first word of each description.