In vampire fiction, depending on the author, one common method of creating another vampire is that the vampire maker must bite the victim on three different nights before the victim becomes a vampire. The victim may or may not gain vampire-like traits with each bite. I have seen this used in the movies Guess What Happened to Count Dracula? (1971) and Once Bitten (1985), the Anita Blake novel series (going back to 1993), and mentioned numerous times in online discussions about vampires. However, I cannot seem to trace when this convention was first codified earlier than the 1971 example.
Your assumption that any vampire traits have been codified in a code of laws for fantasy writer's is unfounded.
Wikipedia has a set of tables of vampire traits in folkore and various works of fiction.
There is a row for each folklore, ficiton, movie, or tv version of vampires, and columns for each trait, and each interesction is marked whether or not that trait is present in that version.
And TV Tropes has a trope called Our Vampires are Different:
And it gives many examples of the different traits of various movie, tv, etc. vampires.
So any particular trait which is common in modern vampire stories is not codified in laws for writers of vampire stories but one which many - but not all - writers chose for various reasons to use in their vampire stories. If two different people happen to read and/or watch different examples of fictional vampires they might come away with different ideas of what a typical vampire is like.
As for biting someone three times turning them into a vampire, it might be a common vampire trope. But the more common a trope might be, the more likely it is that some independent minded, contrarian spirited, writer will deliberately decide to reject or reverse it in their story.
So I wouldn't be surprised if some writer wrote a vampire story where a vampire bits someone on three different nights and turns back into a human instead of turning the human into a vampire!