What is the reference Iri is making when she says DDD?

Question

In Episode 1, Iri and Student 0 have the following conversation:

Student 0: There's no future to it (the War) at all. Why only one team, Instructor? I think everyone should just share it (the Grail).

Iri: There are DDD circumstances behind that, so I'm sorry. I'd like to tell you in greater detail, but it won't happen. It's still too early for you to experience the adult world.

On the chalk board behind her, it shows Dark, Dirty, Dandy.

Since this entire mini-series is cluttered with references to the Fate series, I'm wondering what this DDD means in relation to the Fate series?

Answer 1

I belive it's referring to Decoration Disorder Disconnection, AKA DDD, which is another title written by Kinoko Nasu which was published in Faust magazine

Arika Ishizue lost his left arm in the A-syndrome related accident and hospitalized. After he left the hospital and went back to Shikura, he met a beautiful boy named Kaie Karyou who has no limbs and is living in a dark basement. The boy asked him to exorcise the "Demons" possessing A-Syndrome patients. Arika was involved in the bizarre cases and the fights with the "Demons".

Source: DDD on Typemoon Wikia

As the Wikia also states there are no connections between DDD and the rest of the Natsuverse, even though Mitsuru Kamekura from Kara no Kyoukai is refernced in it as the wiki states

it is simply a gimmick included by Nasu to cause readers of both to do a double-take while reading. It is actually a pseudonym taken from a character in a book in the DDD world.

However i do not know how being able to share the Holy Grail or not is related to DDD or how explaining it is "too adult" for Student 0. however given the case with Mitsuru Kamekura this could be the same thing with it being a gimmick by Kinoko Nasu and/or Gen Urobuchi to cause those who have read DDD to do a double take