It is a generally accepted standard that editors should attempt to follow, though it is best treated with common sense, and occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.
Wikipedia writers and editors contribute a lot of brilliant prose, but occasionally some patent nonsense. This falls into two categories:
Total nonsense, e.g. text that purposefully has no meaning at all (lorem ipsum) and random text (banging on the keyboard).
Content that, while apparently intended to mean something, is so confusing that no reasonable person can be expected to make any sense of it. See word salad. If the meaning cannot be identified, it is impossible to accurately copy-edit the text.
Not to be confused with ...
The following should not be speedily deleted as patent nonsense (though some might meet other speedy-deletion criteria). There are other ways to deal with these things: editing to fix the problem(s); possibly reverting or tagging; or see the deletion policy.
Vandalism (i.e., intentionally harmful edits), including joke edits, hoaxes, (irrelevant) obscenities and other immature material, might (or might not) be patent nonsense, but it still needs to be removed. Other nonsense may be mistakes, badly formatted text, or test edits, without malicious intent, and tact may be needed.
Remove it from the article if there is any acceptable content left in the article after that. Often patent nonsense is easy to undo.
Do consider that it might have been a test edit, and don't bite the newbies by calling them vandals in this case, but instead warn them with a personal note or by using the uw-test series of warning templates (Template:Uw-test1). Where vandal intent is clear warn using the uw-vandalism series of warning templates, and report them as vandals if they continue.
However, if a user objects because they believe the content is not patent nonsense, discuss the issue and try to reach a consensus. In particular, if someone offers to rework the "nonsense" into worthwhile content, please allow them reasonable time to do so.
If a page contains nothing but patent nonsense:
First, examine the page history to determine whether the patent nonsense present replaced other earlier content. If so, restore the page to the latest revision before the content was replaced by patent nonsense. Warn users responsible for introducing patent nonsense as above.