The PKG files for PS5 games include a file named param.json which defines metadata relating to the game. Within the contents of the JSON object are properties named attribute, these define some of the features that the game supports (eg. 120hz output, PS5 Pro support).
At the time of writing there are four attribute properties. attribute attribute2 attribute3 have been present in the file since the release of the PS5. attribute4 was added ~October 2025, and so far it does not appear to be mandatory to include it.
The value for these properties is an unsigned 32bit integer.
The actual features that the game supports are set at the bit level. This means each attribute property has 32 features that can be flagged as enabled or disabled.