Editing Encyclopedia:Redirect (section)

== Vaccine overload ==
<!-- "Vaccine overload" redirects here. -->
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To ensure that a redirect will not break if a section title gets altered, or to create a redirect to a point on the page other than a section heading, create an explicit target anchor in the page, e.g., by using the {{Tl|anchor}} template. Alternative anchors for section headings are ideally placed directly after the name of the heading (but before the closing equals signs):
<syntaxhighlight lang="wikitext">== Section title {{subst:Anchor|anchor name}} ==</syntaxhighlight>

[[Wikipedia:Substitution|Substitution]] (<code><nowiki>{{subst:Anchor}}</nowiki></code>) is preferable to simply using {{tlx|Anchor}} because otherwise, when the section is edited via its own {{nowrap |"[ edit ]"}} link, the anchor markup and alternative section title(s) will appear as undesirable clutter at the beginning of revision history entries.  {{crossref|pw=y|See [[MOS:RENAMESECTION]] for further discussion of this.}}

The anchor text will not be visible on the page, but it will serve as a permanent marker of that place on the page. Editors should generally not remove or alter such anchors without checking all incoming links and redirects. If several logically independent aspects of a topic are discussed under a single section header and should be linked to, it is sometimes useful to define separate anchors for them, if the current amount of information doesn't justify a division into multiple sections already. This makes it easier to rearrange contents on a page as it develops since those anchors can be moved with their corresponding contents without a need to fix up incoming links.

For example, in the [[Google Search]] article, the text {{tnull|anchor|calculator}} is placed at the point where ''Google Calculator'' is discussed. The title [[Google Calculator]] can then be redirected to [[Google Search#calculator]].

When a section title is known to be the target of incoming links, the Wikipedia Manual of Style [[MOS:RENAMESECTION|suggests creating a redundant anchor with the same name as the section title]], so that such links will continue to work even if someone renames the section without creating an anchor with the old name.  Technically, the redundant section and anchor names result in invalid HTML.<ref>{{cite web |title=The id attribute |url= https://www.w3.org/TR/html51/dom.html#the-id-attribute |website=HTML - Living Standard |publisher=[[WHATWG]] |access-date=June 3, 2022}}</ref> However, when a document contains multiple tags with the same <code>id</code> value, browsers are required to return the first one, so in practice, this is not a problem.<ref>{{cite web |title=getElementById |url= https://dom.spec.whatwg.org/#dom-nonelementparentnode-getelementbyid |website=DOM – Living Standard |publisher=[[WHATWG]] |access-date=June 3, 2022}}</ref>

Be careful with anchor capitalization, as redirects are case-sensitive in standards-compliant browsers.<ref>{{cite web |title=Syntax of anchor names |url= http://www.w3.org/TR/html4/struct/links.html#h-12.2.1 |website=HTML 4.01 Specification - W3C Recommendation |date=24 December 1999 |publisher=[[W3C]] |access-date = June 3, 2022}}</ref>
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