From Tolkien Gateway

patakar is a Quenya word meaning "consonants".[1]

The word patakar is a 'Quenyarized' word composed by the sounds /p/, /t/, /k/and refers to voiceless stops.[2] These are the basic glyphs of the Tengwar (Parma, Tinco along with Tyelpë, Calma along with Quessë) and are the heads of each 'series'.

The series are named tincotéma, parmatéma, calmatéma respectively (téma means "series" in Quenya).