Explainations of preferences

This is probably the wrong category for my question but I cannot work out where else it fits so …

Where is there a user-level explanation of the preferences in about:config? For example for media.autoplay.blocking.policy what do the numbers mean? Or app.normany.first_run?

When using about:config it would help greatly if explanitory text were available.

hmm, IMO you should go to your browser : Settings -> Privacy & Security -> scroll down a bit and set the “Autoplay” options there.