Items With Questionable Bonuses

[Jessikha]

There are a few items, when worn alone and checked with a potion of enlightenment, show no benefits. If anyone knows the exact bonuses of the following items, please post what they do here:

-Ring of Greater Protection (and I guess regular RoP as well)
-...I had a brain ****. I'll edit this later when I remember what else I wanted to know, but until then, feel free for to post asking the stats/bonuses of any item, or to answer anyone's query.

Edit: I didn't know that the word to expel gas was censored