Wikipedia:Substitution

Benefits

• If there is a template you would like to modify for a single occasion, but you do not want to modify the template for all the pages that use it, and you do not want to make a new template, you can substitute the template and then with a second edit, make the modifications. For example, a template might be used with all the states of the United States and with the District of Columbia. The template might be worded correctly for the states, but not for DC. To fix the wording, you can substitute the template and then fix the wording.
• Substituting frequently used, but unprotected templates, limits the damage that can be caused by people vandalizing the template. See high-risk templates.
• Transcluding certain templates hides wikitext from newcomers, whereas substituting makes the wikitext visible and gives them the opportunity to learn its use (of course, there is a "how to edit" link at the bottom of each edit page).
• Substitution allows for recursive evaluation through macro templates.

Neutral

• Substituting en masse may ultimately speed up the site, but this is not a reason to prefer substitution over transclusion. Don't worry about performance of Wikipedia's servers.
• Templates are often modified or deleted. If a template is boilerplate text, consider whether you want it to vary as the template is modified. If your answer is "no", substitution is warranted. An example of this is the {{subst:welcome}} template. The archives of a user's talk page should show the actual welcome message they received, not the current welcome message.

Drawbacks

• Once a template is substituted, the result is no longer linked to the template, making it hard to find all pages displaying that text (though categories can sometimes relieve this). The problem can easily be worked around by including a link to the template in the template's code.
• A substituted template will not be updated when errors in the master template are corrected.
• If the template is used to standardize the appearance of something, you probably do not want to do a substitution. An example of this is a table of contents or navigation box.
• Substituting en masse—editing thousands of articles with bots—temporarily slows down the site and wastes server resources unnecessarily.
• Substitution increases the size of articles in the database and database dumps.
• A substituted template can add a lot of wiki-code or HTML to the article, harming accessibility for the less technically inclined.
• Substituting templates prevents newcomers from learning to use templates, and prevents users from finding their documentation.
• If the template is just being used temporarily, it is usually better not to substitute. Substituted templates are much harder to remove or modify.
• When a vandalised template is substituted, it is more difficult to repair than regular vandalism because of the lack of links between the template and its incarnations and the lack of updatability.
• Some meta-templates, such as {{!}} and {{((}}, do not work if they are substituted.

This is a list of templates that should always be substituted, organized by namespace. Each list is ordered alphabetically with grouped series. This is not a comprehensive list; other less-used templates may also need to be substituted, see the template's documentation for details.

Article namespace

• {{No more links}}, substituting this inserts a commentary only visible in edit mode, with a short explanation to discourage spamming links.

Article talk

• {{tmfrom}}, {{tmto}}

User talk namespace

All of the templates listed in Category:User warning templates and Category:Welcome templates should be substituted. This does not apply to templates on the user page.

File namespace

This section is empty. You can help by adding to it.

Misc. templates

• User signature templates, if transcluded, cause undue server strain as changes to a minor user template must then be widely propagated. If used, user signature templates should be substituted. (It should be noted, however, that
  user signature templates are discouraged
  .)

Uncategorized suggestions

This section is empty. You can help by adding to it.

These templates have a purpose and/or syntax that require them to be substituted.

• {{
  afd
  }}, or else the link to "this article's entry" does not work.
• {{cfd}}, {{cfr}}, {{cfm}}, which insert comments which serve as queues for Cydebot, which is used to rename or merge categories.
• {{copyvio}}, for articles to be listed at copyright problems, will result in an error message if transcluded.
• {{
  no license
  }} with today's date automatically filled in.
• {{
  no rationale
  }} with today's date automatically filled in.
• {{
  nsd}}, for images with no source info, adds {{di-no source
  }} with today's date automatically filled in.
• {{
  di-orphaned fair use
  }} with today's date automatically filled in.
• {{
  di-orphaned fair use
  }} with today's date automatically filled in (takes the name of the replacement image as parameter).
• {{proposed deletion}}, for proposed deletion, adds {{proposed deletion/dated}} with today's date automatically filled in.
• {{requested move}}, for requesting page moves
• {{
  rfd
  }}, redirects for discussion
• {{
  replaceable fair use
  }}, with today's date automatically filled in.
• {{refu-c}}, used in captions of images flagged as replaceable fair use, adds {{rfu-c}} with the "due date" (today + 7 days) automatically calculated and filled in.
• {{OnProd}}, which inserts today's-date-dependent name of the category page to which the article was added when nominated for deletion.

Technically, templates should not be substituted that:

1. contain calls to ParserFunctions (#if, #switch, etc.), unless, where possible, these are substituted too (see mw:Manual:Substitution#Multilevel substitution)
2. leave some parameters to their defaults by not specifying them, unless the alternative default mechanism is used
   
3. contain external links as the formatting of the URL to perform queries or look-ups may change

This is because these constructs are not replaced in the generated wiki-code (single level substituting of case (A) leaves the #if or #switch constructs verbatim at the subst location and (B) leaves constructs like {{{1|default value}}}).
If specific

• Various citation/reference templates which contain very complex conditional code (see:
  WP:CITET
  ).
• {{Curlie}}, URL queries external web directories (former DMOZ).
• Infobox templates, various ones for the sake of bot-identification and consistency.
• {{Javadoc:EE}}, {{Javadoc:SE}}, {{Javadoc:SE-guide}}, conditional templates whose purpose is to update the links when the master template is updated.
• {{
  s/wnote
  }}, not messages to the users (so it is no problem if they change from their original form), so no reason to subst, but the standard reasons not to subst apply.
• {{ln}}, {{lnt}}, complex code
• {{Main}}, maintains formatting standard.
• {{switch}}, also conditional templates; substituting breaks usage
• {{See also}}, standard formatting for see also list
• {{
  selfref
  }}, does not work when substed, as it is meant to contain different code in mirrors.
• {{Signpost-subscription}}, must be updated weekly.
• {{stub}} templates, various ones for simplified usage and removal
• {{
  talkarchive}}, {{archive
  }}
• {{
  tl
  }} with over 7,010,000 transclusions at last count. Quicker to type than their substitutions, and non-substing them allows new Wikipedians to learn about them and be able to use them.
• {{sockpuppet}} and similar templates intended to be placed on the top level page in user space. (Note: warnings and notices in the user talk space should be substituted.)

Note also that some things may appear to be templates but are actually magic words, such as {{!}} and {{noexternallanglinks}}. Substituting them either will output nothing, or will substitute a template that shadows them (like the deprecated Template:!).

Wrong title templates

These templates, used in the main-space, add a comment about why an article is misnamed. They may be removed as the MediaWiki titling facilities improve, and the wording/layout may change.

• {{correct title}}
• {{
  lowercase
  }}

Deletion-related

Most templates related to renaming or deleting pages are used temporarily, and thus do not need to be substituted (it just makes more work to delete them).

• {{catfd}}
• {{
  idw-cp
  }}
• {{
  cfdnotice
  }}
• {{sfd-t}} {{sfd-r}} {{sfr-t}}
• {{
  prod-2
  }}
• and all in Category:Speedy deletion templates
• {{
  editprotected
  }} not deletion related, but also temporary

Exceptions

The following templates must be substituted in order to work correctly:

• {{
  afd}} {{afd2}} {{afd3
  }}
• {{cfd}} {{cfm}} {{cfr}} {{cfr-speedy}}
• {{
  nsd
  }}
• {{
  prod
  }}
• {{
  rfd
  }}
• {{
  tfdnotice
  }}

In addition, those templates which document a finished deletion process ({{afd top}}, etc.) should be substituted.

• {{col-begin}} {{col-2}} {{col-3}} {{col-4}} {{col-end}}
• {{
  Clearright
  }}
• {{
  ed2}} {{ed right}} {{edit
  }}, simplify addition of edit link to templates.
• {{
  discussion bottom
  }}

This page is referenced in the Wikipedia Glossary.

• Help:Substitution
• meta:Help:Substitution, a longer and more technical help page at Meta
• Special:ExpandTemplates (put the template with the brackets {{ }} in the "input text" box).
• Category:Wikipedia substituted templates
• {{
  Subst only}} (placed on the {{documentation subpage
  }}, not the template pages, of templates that need to be substituted rather than transcluded)
• AnomieBOT, a bot approved to substitute certain templates.