Meta Elements

Meta elements are a way of adding additional meta data to an HTML document. The are to be put in the <head> section of the page. The keywords, as well as the values are case-insensitive.

List of possible Meta elements on the page

The following list gives examples of meta elements to be used on web pages and a description of their purpose. This list is, by no means, exhaustive and attempts to just list the most common ones. For further information and more meta elements, please refer to the resources listed at the bottom.

Content-Type

Defines the format in which the page is served, e.g. text/html and the character set being used.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

Content-Language

Used to determine the primary language(s) of the content (ISO 639-2 Language Code List).

<meta http-equiv="Content-Language" content="en-us" />

Author

Name of the author of the page

<meta name="author" content="Klaus Komenda" />

Copyright

<meta name="Copyright" content="Copyright (c) 2000-2008 Klaus Komenda" />

Keywords

The keywords attribute was pretty popular with search engines in the mid-nineties, but it was quickly abused by webmasters to put all sorts of keywords in that meta element, that did not even closely relate to the content of the page.

Consequently the importance of that element diminished and it is currently up for debate whether it makes a difference in search engine rankings.

<meta name="keywords" content="" />

Description

Unlike the keyword attribute, the description attribute is supported by most major search engines and should consist of a precise explanation about what the page is about. It should be less than 156 characters, as search engines are unlikely to display more in their search result pages.

<meta name="description" content="The personal weblog of Klaus Komenda, a Web Developer from Vienna, Austria." />

Imagetoolbar

IE6 shows for images larger than 130 x 130 pixels a in image toolbar when the user hover over the image. Setting this Meta element prevents this.

<meta http-equiv="imagetoolbar" content="false" />

PICS-Label

The PICS specification enables labels (metadata) to be associated with Internet content. It was originally designed to help parents and teachers control what children access on the Internet, but it also facilitates other uses for labels, including code signing and privacy. The PICS platform is one on which other rating services and filtering software have been built.

<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l r (cz 1 lz 1 nz 1 oz 1 vz 1) gen true for "http://www.yahoo.com" r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l r (n 0 s 0 v 0 l 0) gen true for "http://www.yahoo.com" r (n 0 s 0 v 0 l 0))'>

Robots

Settings for search engine bots as to how the page should be indexed. The content field is a comma separated list. Alternatively, the behaviour of search engine bots should be controlled by creating a robots.txt.

all: search engine bots should include the current page as well as all other pages linked on this page within the current site in the search index. This is the default and equivalent to leaving it empty, i.e. content=”".
index: search engine robots should include this page.
follow: robots should follow links from this page to other pages.
noindex: links can be explored, although the page is not indexed.
nofollow: the page can be indexed, but no links are explored.
none: robots can ignore the page. (= “noindex, nofollow”)
noarchive: Google uses this to prevent archiving of the page.

<meta name="robots" content="noindex, follow" />

Viewport

<meta name="viewport" content="width=742" />

Can be used to match the viewport to the width of the content of the page, especially useful for iPhone.

MSSmartTagsPreventParsing

Prevent “intelligent” modification of the page when viewing it in IE (adding links to words on the page which might be related to MS products)

<meta name="MSSmartTagsPreventParsing" content="true" />

ICBM

<meta name="ICBM" content="40.746990, -73.980537" />

Das ICBM Tag (für: intercontinental ballistic missile) ist ein Pendant zum geo.position Tag, existiert aber schon wesentlich länger und ist daher weit verbreitet. Die Notation ist wie beim geo.position Tag, lediglich als Trennzeichen zwischen Latitude und Longitude wird kein Semikolon sondern ein Komma verwendet. Wenn beide Tags also ICBM und geo.position verwendet werden, was durchaus Sinn macht, dann sollten die Koordinaten natürlich übereinstimmen.

DC.title

A name given to the resource

<meta name="DC.title" content="Klaus Komenda: Personal Weblog" />

DC.subject

A topic of the content of the resource.

<meta name="DC.subject" content="Web Development" />

DC.creator

An entity primarily responsible for making the content of the resource.

<meta name="DC.creator" content="Klaus Komenda - http://www.klauskomenda.com" />

More information about he Dublin Core Initiative can be found on their website and at seoconsultants.com.