N – any N, NP, nominal clause, any nominal (need not be a noun but can be substituted by one)
ADJ- adjective (Adj) or AdjP, any adjectival
V – predicator
SC - subjective complement (also Cs), meaning ‘that which describes the subject’, an obligatory part
N1- both nouns refer to the same object or entity
ADV - adverb, AdvP, PP, adverbial clause, any adverbial modifier of place and time
AM - adverbial modifier (= modifier of the verb), an obligatory part