A tagset is a list of part-of-speech tags (POS tags for short), i.e. labels used to indicate the part of speech and sometimes also other grammatical categories (case, tense etc.) of each token in a text corpus.

Irish RFTagger part-of-speech tagset

Irish RFTagger part-of-speech tagset is available in Irish corpora annotated by the tool RFTagger trained on Irish Universal Dependencies Treebank.

An Example of a tag in the CQL concordance search box: [tag="(NOUN|PROPN).*"] finds all nouns and proper names, e.g. people, years (note: please make sure that you use straight double quotation marks)

Basic part-of-speech tagset summary

Description Part-of-speech tag
adjective ADJ.*
adverb ADV.*
conjunction (CCONJ|SCONJ).*
determiner DET.*
noun (NOUN|PROPN).*
numeral NUM.*
particle PART.*
preposition ADP.*
pronoun PRON.*
verb (VERB|AUX).*

https://universaldependencies.org/ga/index.html