This page documents an English Wikipedia content guideline. It is a generally accepted standard that editors should attempt to follow, though it is best treated with common sense and the occasional exception. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.
This page in a nutshell: Disclaimers should not be used in articles. All articles are covered by a general disclaimer.
Actually, all articles should have a disclaimer, but it is already at the bottom of this page and every page. See the link on this page that points to Wikipedia:General disclaimer.
From time to time, editors insert disclaimer text into an article or propose a new disclaimer template - for instance, "This article contains profanity" or "This article is not suitable for children". Ideas like this are somewhat of a perennial proposal, but the consensus is that they should not be used. Disclaimer text in encyclopedia articles should generally be removed, and templates of this nature can be removed and deleted.
There are a few exceptions to this:
"technical" disclaimers assisting the user with display problems, such as {{Contains Indic text}}. These do not refer to article content but to issues related to the proper display of article content.
temporal templates such as {{current}} or {{future film}}. These alert the reader that the article content may be subject to significant changes in the near future for reasons beyond the control of Wikipedia.
Some article message box templates, such as {{NPOV}}, {{OR}} or {{cleanup}}, are technically disclaimers, but they are by design temporary, pointing to issues with the article that need to be resolved as soon as possible. No FA-quality article may include any article issue templates.
For the purpose of this guideline, disclaimers are templates or text inserted into an article that duplicates the information at one of the five standard disclaimer pages:
Hard to define which articles should have a disclaimer (it is difficult to define an "adult content" article, for instance, given that it varies dramatically by culture). Allowing some disclaimers would generate a significant overhead of disputes surrounding where to draw the line, drawing editors' time from more productive tasks.
The lack of the disclaimer on certain pages as opposed to others might open Wikipedia to lawsuits.
By the time you see them, it's too late — the article has already been loaded.
They take up enormous amounts of page space when used in banner form.
Minority opinions in favour of allowing disclaimers in certain cases that have been forwarded in these discussions include:
People might be upset by seeing certain content on Wikipedia. (For a discussion of this see Wikipedia is not censored above).
The user does not know where objectionable or disturbing content may appear, and it may therefore catch them off-guard.
Once you've seen an offensive image, you can't just pretend you never saw it.
The benefits of disclaimers are immediate and would occur often, as opposed to hypothetical lawsuit threats.
Status of this guideline
This guideline represents a solid and long-standing consensus on English Wikipedia. It hasn't been elevated to the status of policy because of the few possible exceptions listed above, and a certain room for disagreement how far precisely these exceptions should be taken.