Kataris
From Battlestar Wiki, the free, open content Battlestar Galactica encyclopedia and episode guide
Kataris was a Caprican poet. Lt. Joe Palladino owns a bound edition of Kataris' poems and threatens Col. Saul Tigh with lines from one:
From the darkness you must fall
Failed and weak, to darkness all. (Final Cut)
Kataris is sufficiently well-known for Kara Thrace to recognize the quotation, recall from which piece it comes, and know the poem's quality relative to his other works, and for D'anna Biers to recognize one of his books on sight in a videotape recording.
Note
The name "Kataris" is probably a reference to the Roman poet Catullus.