The video codec used to compress the file. XviD was a standard for Standard Definition (SD) video for many years.
A tag used by scene groups to indicate the release might not meet certain standard "scene rules" or is a secondary release for a specific reason. Watch Helix S02E10 INTERNAL HDTV XviD-AFG-[GTtvSD]
If you are looking to watch this, Helix is often available via major streaming platforms like Hulu, Amazon Prime Video, or through physical media. The video codec used to compress the file
The show title ( Helix ), Season 2, Episode 10 (titled "Mother"). Amazon Prime Video