The reason keywords surrounding God of War PKGs are so popular is due to the game's status as a technical benchmark for the PS4.

The string refers to the App Type. In PS4 package nomenclature, the system distinguishes between different kinds of content. A generally stands for "Application" (the main game executable), as opposed to "Patch" or "Addon" (DLC). This confirms that the file is the full standalone game, not an update file or a DLC pack.

The string you provided refers to a specific digital package file (PKG) for the on the PlayStation 4