User blog comment:Martialmaniac/Inferred Nen Type/@comment-4932025-20160620002148

Inferred Nen types of abilities and symbol/reference = Ok, but it's gonna get really out of hand with Gon-san, sun and moon and all that jazz we have left unknown as of now.

Inferred Nen types for characters = No, if it's unknown it stays unknown, you can't give them a Nen type only based on what typing their abilities are, just look at Netero alright. The only exception for this would maybe be specialists.

"it is not at all sure Meruem is a Specialist"

I've already talked about this, there is a reference next to it saying that it's from Battle Collection, no one forces you to think it's canon but it's still the only remotely official statement regarding his Nen type, the Yu Yu Hakusho booklets just call it "???"

''"particularly because his ability to increase his aura by eating Nen users may be just a variation of phagogenesis (species ability) and not a Nen ability." ''

Sure, wanna separate it from the rest of his actual Nen abilities? I wouldn't mind, I myself think it's a natural ability and maybe the same goes for Youpi, but just because that ability isn't specialization doesn't negate the fact that Battle collection called him a specialist.