I am pretty sure Moon Circlet should take up the head slot:
The head slot consists of caps, circlets, crowns, halos, hats, helms, hoods, laurels, masks, veils, wigs, and other non-headband slot items that can be worn on the head.
But in its item entry it is listed as taking up the headband slot:
Aura strong evocation; CL 15th
Slot headband; Price 20,000 gp; Weight —
Description
This fine silver circlet typically has a carved moonstone inset on the front or a crescent moon design. The wearer of a moon circlet gains darkvision out to 60 feet (if she does not already possess it). Its other effects only benefit a wearer capable of casting arcane spells.During the waxing moon, the wearer’s caster level is considered one higher for purposes of caster level checks and spell effects; during the three nights of the full moon, this benefit increases to two levels higher than normal. However, this additional power comes with a price. During the waning moon, the wearer’s caster level is considered one lower for purposes of caster level checks and spell effects, and during the three nights of the new moon, this penalty increases to two levels lower.
Removing a moon circlet imposes 2 negative levels on the wearer until the next full moon (or until the circlet is worn again, whichever comes first). These negative levels cannot be restored by any means short of a limited wish, wish, or miracle.
Construction
Requirements Craft Wondrous Item, darkvision, light; Cost 10,000 gp
So which should it take up?
Is this an example of specific trumping general? Or a clerical error that should be overlooked?Would the answer be different if an item such as Gauntlets of XX were listed as taking up the belt slot?
It would take up whatever slot is mentioned in the item's description. So it takes up the Headband.
One could rule that this is a typo, but this has been around since the APG was released. So quite frankly, if it was meant to be a Head slot, then I'm sure somebody would've noted it and it would've been errata'd.
Also, there are some Headband items listed as an "Eye" or a "Band," which can certainly refer to a Ring of sorts.
There are also bonebreaker gauntlets that take up the wrist slot.
Some items just don't use "normal" slots.