Editors should generally follow it, though exceptions may apply. Substantive edits to this page should reflect consensus. When in doubt, discuss first on this guideline's talk page.
This page in a nutshell: Wikipedia writers and editors improve articles in the site, but sometimes, they contribute patent nonsense. There are various ways to deal with patent nonsense.
Wikipedia writers and editors contribute a lot of featured and good articles, but occasionally, they contribute some patent nonsense. This falls into two categories:
Total nonsense, e.g. text that purposefully has no relevant meaning at all (e.g. 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, such as "The land attests that agriculture shafts the uncontrollably mild delicacy and wistfully inanimates the fresh spruce tango jumpsuit impressively in one month" (see word salad). If the meaning cannot be identified, it is impossible to accurately copy-edit the text.
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.
Disinformation and factual errors, including citations to unreliable sources.
Libelous, defamatory, or slanderous comments, no matter how silly. They should be removed immediately if not supported by a reliable source, and possibly revision deleted by an administrator. In extreme cases, libellous edits may be suppressed, making that information hidden even to administrators. See Wikipedia:Biographies of living persons.
Poorly written content that could be improved, such as text containing many grammar errors. See Wikipedia:Basic copyediting.
Text without links. Consider tagging it with {{Underlinked}}.
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.