Necromancer's Athame spontaneous ability

Does it need to be held or used in some way to spontaneously transform necromancy spells or just be on your person? It does not state that it needs to be held, and I don't know if there are standardized rules to fall back on in the case that the item does not clarify.

NECROMANCER'S ATHAME
Aura strong necromancy; CL 11th
Slot none; Price 20,000 gp; Weight 2 lbs.
DESCRIPTION
This pallid length of sharpened thighbone is carved into the shape of a dagger, but with tiny holes bored into it at equal intervals, almost like a flute. A necromancer who selects the athame as his bonded object can use it to spontaneously convert any prepared wizard necromancy spell into any other wizard necromancy spell he knows; the desired spell must be of the same level or lower than the prepared spell.

CONSTRUCTION
Requirements Craft Wondrous Item, create undead, creator must be a necromancer; Cost 10,000 gp

Bolding my own.

It works as the bonded object in a wizards arcane bond:

Wizards who select a bonded object begin play with one at no cost. Objects that are the subject of an arcane bond must fall into one of the following categories: amulet, ring, staff, wand, or weapon. These objects are always masterwork quality. Weapons acquired at 1st level are not made of any special material. If the object is an amulet or ring, it must be worn to have effect, while staves, wands, and weapons must be wielded. If a wizard attempts to cast a spell without his bonded object worn or in hand, he must make a concentration check or lose the spell. The DC for this check is equal to 20 + the spell's level. If the object is a ring or amulet, it occupies the ring or neck slot accordingly.

Bolding my own.

The Athame is not classified as a weapon, stave or wand, so on your person it is.

http://www.d20pfsrd.com/magic-items/wondrous-items/wondrous-items/m-p/necro mancer-s-athame

It's a slotless wondrous item, shaped like a weapon it may be, it cannot be used as one so it does not classify as one. It also does not fall under any of the bonded object categories but states it can be used as a bonded object as an "Athame" specifically. This is the reason for the question, the obvious sources of information were already checked.

Sorry, I was unclear in my explanation. Yes, because it is slotless it just has to be "equipped". Meaning that it has to be about your person to be useable. The passage from the arcane bond was to show that the classifications they list show that it has to be worn like an amulet or ring, and since it is a slotless wondrous item then it just has to be on your person.

Hope that makes more sense!

That makes more sense, I thought it had to fall under one of the categories listed under arcane bond. Thanks for clarifying.