When should a trope have a The

I came across the page for "The Book Cipher" trope while I was creating a page for "Our Man in Havana". Is there a reason that it's "Book Cipher" rather than just "Book Cipher"? Is there a rule for what tropes would have a "The" or not? Obviously, some need it ("The Ace", "The Cape"), but for The Book Cipher in particular, I'm not sure what's gained from keeping the definite article in the title.

I do not know why The Book Cipher has a "The". It wasn't a point of discussion on the draft page, but it was also 2011 when the trope was launched.

Found on The "The" Title Confusion:

• TV Tropes has run into this a few times; "The" is usually omitted from a name unless it is a character type (The Dragon, The Pollyanna) or part of a set phrase (The Blind Leading the Blind). Back when character names were accepted as trope titles, "The" was used to distinguish, say, The Ralph Wiggum (a humorously stupid person) from Ralph Wiggum (the Simpsons character). Pages' search-engine descriptions take such forms as "The The Starscream trope as used in popular culture, with a list of examples from all media." Or better yet, for this page, "The The The Title Confusion trope as used in popular culture, with a list of examples from all media."

Trope-Namer Syndrome was a large problem back in the day so I'm assuming the title was meant to copy that style.

It seems pretty arbitrary, and I suspect in a lot of cases, a name with a "the" simply happened to be the one floated during creation and no-one questioned it.

My personal pet peeve is The Food Poisoning Incident. The "the" adds nothing, and seems to imply that it's such an Omnipresent Trope that you can expect it to show up in every work.

Also, it's a code, not a cipher.