A Meta Tag is a line of HTML code used to provide metadata about a web page. What is metadata? Basically it’s data about data – information about information. The metadata in a website page’s Meta Tags contain information about the page designed to classify it. What the page is about, who wrote it, what language is it in, what program was used to create it, etc. Meta tags can also be read by browsers and can pass information on to them about how to display a page, or reload or redirect it. They’re not visible on the web page, and are found between the tags of a document. These meta elements are completely optional, and due to early abuse, now contribute little to a site’s search engine rankings.
The general purpose of a meta tag is to tell web crawlers and search engine bots about the content of a page. If meta tags were being created for this page they might look something like this…
The meta tags once used for SEO purposes, the keyword and description tags, were used to convey what their names imply. Information about what keywords best describe the content of the page, and an actual description of the page. In the early days of search engines, some SEOs and site owners used to stuff the keyword and description tags full of keywords in an attempt to improve search engine rankings. Or worse, used keywords that did not pertain to the sites content at all, attempting to grab traffic seeking something else. These abuses forced the engines to gradually reduce their importance and finally dump them out of their algorithms all together. The keyword tag is no longer used by the major search engines and is completely unnecessary. There is some speculation that some may still consider it, but Google has stated that is not a factor.
The contents of the description tag also have little or no impact at all on search engine rankings, but is still an important element of a page as it can be displayed in search results as a description of the page. Creating unique meta description tags for every page of a website, ensuring that they are enticing and click-worthy is an important part of search engine optimization.
There are a lot of meta tags, but most of them are not read or used by any search engines. For example, there’s absolutely no reason to use an Abstract, Author, Copyright, Distribution, Expires, or Revisit tag. That last one is particularly useless – no search engine is ever going to allow a random meta tag to dictate when it re-crawls the page.
However, they do pay attention to the robots meta tag, which you can use to tell the search engines any preferences you have about the indexing of an individual page. “Robots” is referring to search engine bots, or crawlers, that visit your site and collect data for their search engine’s database. The robots tag allows you to tell the bots that there are certain pages you would like them to not index, certain pages that you would like them to not follow links from, and many more indexing options.
Some useful Robots tag options are:
- noindex: prevents the page from being indexed and listed in search engines
- nofollow: prevents the bot from following links on this page
- noarchive: prevents search engines from keeping a cached copy of the page in their database to show to searchers
- nosnippet: prevents a snippet (usually showing instances of the keywords being searched) from being shown in the search results instead of your site’s description tag
- noimageindex: prevents indexing of images (in theory, apparently not too effective)
- noodp: will prevent your site’s title or description from being overwritten by its Open Directory (dmoz.org) listing
- noydir- will prevent your Yahoo Directory listing from overwriting your site in Yahoo web search results.
A robots.txt document is a more effective way to impart this information to the bots, and generally the method that search engines claim to prefer, though if there’s only a page or two you have specific instruction for, this might be the way to go. There’s absolutely no reason to use a robots tag on any pages of your site if there is nothing you don’t want crawled, and there’s no other specific thing you want to prevent the search engine from doing. Despite the positive follow/index options for the robots tag, you do not need to tell the bots to index a page or follow the links on it – that’s what they do by default.
A meta refresh tag, can be used to tell the browser to redirect the page to another page after a certain period of time. The refresh tag is really not recommended, at least from an SEO perspective. Search engines don’t like them because they’ve been abused in the past by people setting up multiple entry pages that all redirect to the same page, so they have the potential to cause big indexing problems.
Using a meta tag that is incorrectly formatted or not acknowledged or known to a search engine shouldn’t pose any problems. The general rule is that search engines will simply ignore anything they don’t understand.