''Any specialised wiki, as it continues to grow, will tend to accumulate general, more encyclopedic, information.''

For every wiki out there that exists by TheWikiRule there is the issue of some additional knowledge not exactly under the main mission of the site still being very useful for understanding the behaviour of the site's focus. There's also the fact that the internet exists globally while a wiki's contributors can exhibit local variations in behaviour and these often have to be explained.

For example, our UsefulNotes pages exist to help people understand things that may be taken for granted under the CreatorProvincialism of other contributors or of TV writers. It started with issues of geography and then extended to subjects that have a complex relationship with their portrayal in media. Things which it is useful to know in order to understand everything that is written hence UsefulNotes. Even before this, we also have pages on [[{{Trivia}} production trivia]] and [[YMMV/HomePage audience reactions]], which are not in fact tropes by themselves but which still impact on how stories are written such as ExecutiveMeddling and the {{Fandom}} tropes.

This effect dates back to the original wiki, Ward Cunningham's [[http://c2.com/cgi/wiki?WikiWikiWeb Wiki Wiki Web]]. There were enough SeparatedByACommonLanguage problems that users felt the need to create a page explaining "American Cultural Assumptions"... which turned out to be similar to our UsefulNotes pages.

!! Examples:
* [[http://www.halopedia.org Halopedia]], the ''Franchise/{{Halo}}'' wiki, has a page on corn, as well as other things, due to it being an inclusive wiki.
* The [[Wiki/TFWikiDotNet Transformers Wiki]] has a lot of information on toy production and technology. The Transformers Wiki also has pages for [[http://tfwiki.net/wiki/Jesus Jesus]] (probably existing to service the comparisons between Optimus Prime and Him) and [[http://tfwiki.net/wiki/Michael_Jackson Michael Jackson]]. Hilariously, it pointedly does ''not'' include any information that does not show up directly in ''Transformers''-related media, even if it would be relevant general knowledge otherwise.
-->[[http://tfwiki.net/wiki/Darth_Vader [Darth Vader, aka Anakin Skywalker]]] [[LukeIAmYourFather is presumably related to]] the similarly named [[Franchise/StarWars Luke Skywalker]] in some way.
* Wookiepedia, the ''Franchise/StarWars'' wiki, includes pages on gender and death, among other things. It even an article on breasts, which has caused quite a bit of problems when outside forces came to the site's community complaining about it.
* Wiki/ThisVeryWiki used to stick to television, [[ArtifactTitle hence the name]]. Now it covers tropes from all conceivable media, and [[UsefulNotes some things]] that aren't technically tropes at all.
* Since ''Franchise/DonkeyKong'' exists in the same universe as ''Franchise/SuperMarioBros'', it isn't surprising that the [[http://www.mariowiki.com/Main_Page Super Mario Wiki]] would have some information on the ''DK'' characters and games. However, it has ''extensive'' information on everything ''Donkey Kong''-related, even more than the actual [[http://donkeykongwiki.com/Main_Page Donkey Kong wiki]]. The wiki even has pages for characters in series such as ''Franchise/TheLegendOfZelda'', ''Franchise/{{Metroid}}'', ''Franchise/FireEmblem'', and many others due to their inclusion in ''VideoGame/SuperSmashBros'', which the wiki kinda treats as a sort of ''Mario'' subseries/spinoff.
* The ''Franchise/HarryPotter'' [[http://harrypotter.wikia.com/ Wiki]] has [[http://harrypotter.wikia.com/wiki/Category:In-universe_articles_on_real_subjects several articles like this]] for anything mentioned or shown in ''Franchise/HarryPotter'', including [[http://harrypotter.wikia.com/wiki/Game_Boy the Game Boy]], [[http://harrypotter.wikia.com/wiki/Electricity Electricity]], and [[http://harrypotter.wikia.com/wiki/Stephen_Hawking Stephen Hawking]].
* [[http://doomwiki.org/wiki/Entryway The Doom Wiki]], which gives an equal regards to the narrative, historical and [[GameEngine technical aspects]] of the ''VideoGame/{{Doom}}'' series, also completely documents the narratively seperate ''VideoGame/{{Heretic}}'', ''VideoGame/{{Hexen}}'' and ''VideoGame/{{Strife}}'', all of which were programmed on the original ''Doom'' engine, as well as any notable ''Doom'' GameMod. It also has brief pages on ''VideoGame/{{Wolfenstein 3D}}'', the original ''VideoGame/RiseOfTheTriad'', ''VideoGame/QuakeI'', ''Shadowcaster'' and ''VideoGame/RaptorCallOfTheShadows'', who all have a technical history involving the ''Doom'' engine, as well as briefer pages on DuelingGames ''VideoGame/{{Duke Nukem 3D}}'' and ''VideoGame/{{Marathon}}''. It does not, however, covers ''Hexen II'' and ''Heretic II'', which were programmed on ''VideoGame/{{Quake}}'' series engines, nor does it covers any game programmed on ''Doom 3''[='=]s id Tech 4 engine beyond ''Doom 3'' itself.
* [[http://wikizilla.org/wiki/Main_Page Wikizilla]] is the ''Franchise/{{Godzilla}}'' wiki, but it also describes the ''Franchise/{{Gamera}}'' and non-''Film/KingKongVsGodzilla''[=/=]Film/MonsterVerse ''Film/KingKong'' movies in the same depth, and even has entries on a number of completely unrelated {{kaiju}} movies.