Proposed decalogue of the Good Wikipedia Editor:

DM: Always think of Wikipedia's readers.
DE: Fix any contents that you think is wrong.
DD: Delete any contents that you think is inappropriate.
DC: Create any article that you think is important.
DM: Rename any article that you think is misnamed.
DU: Undo any edit that you think should not have been done.
DL: Read other articles and imitate the ones you liked best.
DJ: Always explain your edits in the summary or talk page.
DS: Reference any source that you used for your edits.
DR: Discuss disagreements in the talk page.
DA: If agreement seems impossible, just move away.
DW: Warn users who misbehave by posting on their talk pages.
DV: Report any users who persistently misbehave.
 
NY: Never edit to further your personal agenda.
NX: Never edit to harm Wikipedia.
NZ: Never destroy or hinder valid work by other editors.
NB: Do not use automated tools to edit or create articles.
NX: Do not edit an article or section without reading it.
NU: Do not attempt to achieve uniformity across articles.
NS: You do not have more authority that any other editor.
NT: Your time is no more important than that of another editor.
ND: Never copy the same sentence into more than one article.
NS: Do not waste screen space.
NA: Never leave editorial comments or scaffolding in the article.
NJ: Never cite a guideline to justify your edits.
NR: Do not waste your time reading guidelines.
NW: Do not waste other people's time by writing guidelines.

Several of these principles are simple restatements or corollaries
of Wikpedia's Five Pillars, but some need explanation.

DD: Note that this applies to '''contents''', not '''articles'''.
"Inappropriate" contents includes vandalism, hoaxes, libel,
non-verifiable statements, private info, advertisement, excessive
detail, ephemeral information, and all the things covered by "what
wikipedia is not".

DC: This commandment is meant to replace '''and overturn''' the
"notability" requirement. It says that any topic deserves an article
as long as there is one editor who cares enough about it to create
said article. If someone creates an article on a two-block street in
[[Lagos]] or a short poem published in an obscure Chicago magazine in
1913 --- and can provide at least one piece of verifiable information
in it --- that is reason enough to have an article. Note that this
rule does not exclude the usual requirements about contents, nor other
rules such as NB, NY, ND, NX, ND; so this rule does not open the door
to spam or other trash.

There are two practical reasons to have this rule, rather than the
current "notability" requirement. One is the inevitable and
unnecessary animosity that derives from any attempt to classify things
--- especially people --- into two classes, those that are "worthy"
and those that are "unworthy" or a Wikipedia article. Declaring
someone "non-notable" is a public humiliation that Wikipedia's
anonymous and self-appointed editors have no right to confer on
anyone.

The other reason is that since 2006 Wikipedia has been decaying
due to its failure to recruit new editors. While other causes
may have contributed, the aggressive deletion of non-notable articles 
seems to be a major reason.

DS: This is considerably weaker than "every article should have
references". It simply says that *if* you consulted a specific source
while editing an article, *please* record that source in the article
*so that the next editors will not have to search for it again*. On
the other hand, if you wrote an article based on your knowledge, but
do not remember the source, you are *not* required to search for one.

NX:This rule forbids most robots, including spellchecking and
markup-fixing ones. Such edits do not add anything substantial to the
article, not even the reassurance that comes from it having been read
by other editors. Improving the form of an article gives it a
misleading appearance of quality. Paraphrasing a famous quote,
"articles should not look better than they read."

NU: Given the totally uncoordinated way that articles are created and
edited, uniformity across articles --- whether in style, layout,
sectioning, nomenclature, definitions, etc --- is impossible to
achieve, even approximately. On the other hand, any uniformity that
may exists is unlikely to be noticed, and does add to the value of
Wikipedia to readers. Therefore edits that solely aim to achieve
uniformity across articles waste the time of the editor who does them,
and the time of editors who watch the article.

NS: No editor, even the most experienced veteran admin, can assume or
pretend that his opinion is more authoritative than that of any
editor, even the most naive principiant. If for nothing else, the
"principiant" is often an expert in some subject, and the "expert" is
often flatly wrong.

NT: One consequence of this principle is that you should *never* demand
that someone else do something: if you think it must be done, then 
do it yourself.  A corollary of that corollary is that all editorial
tags should be deleted. 

ND: Repeating the same text in several articles lowers the information
density and "think density" of Wikipedia (the number of collective
brain-seconds that went into each word). Even when one article
contains a summary of another article, the two texts must be written
independently. This rule especially forbids templates that generate
text other than what is in the template call itself (template name,
argument names, and argument values). A good template should only
output its arguments with special markup, or generate text that does
not show up in the article. For example, {{tl|chem}} is a good
template, because {{tl|chem|H|3|O|2|+}} expands to {{chem|H|3|O|2|+}}.
The {{lt|doi}} template is good, because
{{tl|doi|10.1021/ja00428a043}} expands into
{{doi|10.1021/ja00428a043}}. The current {{stub}} templates are all
throughly bad, because they expand into a canned text "This article is
a stub...". And so are all editorial templates; which is another
reason why they should be deleted.  This rule also forbids navboxes,
and any canned text in infoboxes (such as "All values are measured at standard
room conditions.")

NS: Do not use layouts or devices that are wasteful of screen space.
For example, the {{tl|main}} tag wastes two lines to say something
that is implied by the section header above and the paragraph below it:

:'''Brazil in the Colonial period''' 
:{{main:Brazilian Colonial period}}
:In the Colonial period, Brazil was....
  
Instead use a plain wikilink in the latter:

:'''Brazil in the Colonial period''' 
:In the [[Brazilian Colonial period|Colonial period]], Brazil was...

This rule also forbids the use of icons. Icons are atention-grabbing
devices and are good for things like buttons that must be found when
mixed into a random bag of other things. They have no place in
articles: we do not want to grab the reader's attention away from the
text, and section headers should be sufficiently clear form him to
find what he wants from the TOC. Besides an icon takes up the space of
half a dozen words or more to say the equivalent of one word.