Certain franchises, and/or characters, due to their long running statuses and great popularity, often coupled with dozens if not hundreds of writers over the decades, find themselves containing numerous versions of their characters, most of which display vastly different levels of power.
The most extreme examples of this are Marvel Comics and DC Comics, that not only contain hundreds of comicbook versions of their characters, due to their multiverses, but also have numerous adaptations in movies, live-action television series, animation, and video games.
Certain anime & manga franchises also run into similar problems. For instance, Dragon Ball possesses numerous alternative continuity games, and non-canon movies. Other large scale franchises often run into similar problems, containing numerous non-canonical spin-offs and alternate continuities.
However, problem can arise from this: If one were to allow all alternate and/or non-canon versions of said characters, we would eventually be crowded with dozens of alternate profiles for the same characters, as well as composite profiles that cross-scale across multiple continuities and inflate the number of pages even more.
As such, certain limitations must be placed:
1) Certain franchises feature several characters that are considered as equally valid "official" versions of the character. These types of profiles can generally be created without any problems.
Ex: The Golden Age, Silver Age, and Post-Crisis versions of Superman, and the different incarnations of Link from The Legend of Zelda.
2) Alternative Canon/Non-Canonical profiles for Marvel and DC Comics can only be created if the version in question proves relevant/notable enough, either through popularity, number of issues present or an immense power discrepancy.
Ex: Superman from the Kingdom Come storyline, and All-Star Superman are relevant enough to warrant profiles, and have displayed enough feats and information for reasonably accurate statistics. Meanwhile, characters from Marvel's random alternative "What If?" timelines are generally far too limited in relevance, appearances, and feats to be featured.
3) Should said alternative versions originate within the main continuity, they would also be considered primary canon, and allowed, if notable enough.
Ex: Thought Robot/Cosmic Armor Superman, the DC One Million characters, and the Earth-3 Crime Syndicate of America all originate within mainstream comics, and feature interactions with the primary DC Characters. Similarly, the Marvel Ultimate Universe was a prominent comicbook line for a considerable time, and the two continuities have recently merged into one, so profiles from said verse are also allowed, as long as proper feats and scaling can be found for the statistics.
4) Franchises which contain non-canonical spin-offs/movies/videogames, etcetera, each with their own continuities and feats, yet not to the extent that Marvel and DC Comics do, should only be allowed profiles for notable original characters from said spin-offs, and not alternate versions of canonical characters, unless they are very prominent and notable.
Ex: Main villains from non-canonical movies of Dragon Ball, Sailor Moon, One Piece and the like can be allowed profiles, yet most versions of Son Goku contained in games such as Xenoverse and Shin Budokai should not, as the only difference they hold from Canon Goku lies in their extent of power. However, given the prominence and popularity of Dragon Ball GT, alternative versions of Goku and Vegeta from this continuity have been allowed. If the alternate non-canonical version of a character is notable enough in the sense of having their own feats, and a different role and purpose, then it is possible that profiles for them can be created.
5) Certain franchises also contain a variety of spin-offs and alternate continuities, yet justify their existence due to in-series Multiverses. In such cases, Rule Number 3 still applies, albeit to a lesser scale. Original characters from said works are all allowed, yet alternate versions of original canon characters should not be abused.
The key issue overall is notability/relevance. If a spin-off version of a character is very popular, prominent, and distinctive from the original, with a sufficient number of feats or descriptions to scale from, it can generally be featured.
However, if it is obscure, does not have enough of a distinctive story to even qualify as a separate character (such as if it originates within a fighting game), and very limited information to scale the statistics from, it should likely not be featured.
The regulations here are less complicated.
Composite profiles should generally only be given to extremely prominent well-known characters with multiple incarnations, and these should only go by their own highest statistics. That means that external weapons and power-sources, that are not a normal part of their arsenal, should be excluded.
This type should preferably be gauged on a case-by-case basis, and you should first ask the staff if it is acceptable to create one.
It can also be justified if a certain fiction has multiple spinoffs of dubious canonicity, for which quantifiable feats are scarce, such as most Pokémon and Digimon characters. It should preferably be limited to franchises that actually need it for sufficient scaling, if the different versions are too dispersed and incoherent to make a clear picture of individually
When writing a composite character profile, it should generally be assumed that all sources are equally canon, and as such can be used to contradict each other. When there is equal consistency for both supporting and contradicting evidence, a canon hierarchy should be issued and the primary source take absolute priority.
Please refrain from writing composite profiles for Marvel or DC characters like Superman or Spider-Man. This is due to the massive number of unimportant versions from alternative timelines, and resulting potential highly inflated statistics and powers and abilities sections, which can set bad precedents for the wiki, and result in bad blood from fans of other franchises.