If this was found in a downloads folder or a shared drive, it may simply be an automated filename from a screen recording tool or a video converter that hadn't been manually renamed.

Many DVR and NVR systems (like those from Lorex or Swann) use alphanumeric prefixes like "g" followed by a channel number and sequence to name exported clips.

High-end cameras or dashcams sometimes use specific codes for folders and files. For example, GoPro uses prefixes like "GOPR" or "GH," but other brands may use custom alphanumeric strings like "G371" to categorize batches or date-based folders.