This is the 326th most frequent Catalan word.
pocs
Few.
Here, 'pocs' refers to a small number of people who registered, acting as a pronoun.
Pocs s'han apuntat a la competició.
Few have signed up for the competition.
'Pocs' in this context acts as a pronoun indicating a limited quantity of individuals.
Vaig veure pocs que estiguessin interessats.
I saw few who were interested.
In this sentence, 'pocs' is used as an adjective to quantify a small number of books.