It is too easy to miss an item with a RR or guild gem slot right now. I would suggest that some symbol be placed on either the item's icon or in the item's name.
An asterix following (or preceeding) and item name would be simple and good enought o show that the item is either race restricted or has a guild gem slot. Alternatively, a small symbol on the item icon itself would suffice. Something (anything) to show at a glance that one of the 20 items on a reward list is special in such ways would be most welcome.
In addition, any item with a guild slot should be able to fit in a gem of smaller size (if this is not currently the case). Got a large slot on a cloak? You can now shove a tiny to medium gem in there.