QA

QA is short for Quality Assurance.

This is an internal NCSoft step in the development process. Essentially, a patch or update will hit QA prior to going to the PTS. There is presumably an interal NCSoft game server where the QA personnel play and test the pre-release patch. If the game passes QA, it goes on to the PTS; if it fails, it goes back to the Devs for rework.