The idea of meta tags was a good one: you invisibly ‘tag’ a document with a description and keywords to enable search engines (and other automated agents) to understand better how to index your document or what the document is about. Humans being humans, meta tags were quickly subverted by unethical people to include irrelevant words (and even competitors’ names or product names) in order to hijack search engine results.

Rather predictably, search engines dropped their focus on meta tags to concentrate on stuff that’s harder to subvert: the text on the page. As a result, it’s often said that meta tags are irrelevant. But that’s not actually the case – and misuse of meta tags can actually negatively impact your search engine results.

The two main meta tags which people recognise are ‘keywords’ and ‘description’. However, it’s not quite true to say that neither of these is used.

Keywords are still parsed by some search engines, but the only keywords which are typically taken into account are those which are already on the page as visible text – so it’s pretty pointless trying to skew search engine results by adding additional terms.

The description can have an interesting (and pretty dire) negative effect if incorrectly used. If you include a description meta tag, it will often be used as the snippet of text that appears in the search engine results pages, below your page title. This is useful – it allows a more accurate précis of the page to be displayed than would be if a random snippet of text is chosen. Some websites use the same meta description for all the pages of a website (well, it does save a lot of work) and that’s where the real pitfall lies. If you do this, search engines can make an understandable assumption that all of the pages of your site are actually very similar – and then pages other than your home page are not properly ranked or indexed. Far better to not include a meta description than to use the same one on every page. But, better still to have a separate meta description on every page – if you’re using a content management system, this can be automated – perhaps by using the content of a specific heading as the meta description.

Although the page title is not a meta tag as such, it is often referred to as one – and this is one tag that’s vital to get right. Page titles carry a lot of weight with search engines and are essential for search engines to fully differentiate pages on your website. Also, when multiple pages from your website are shown in the search engine results, having clearly different titles enables people to see what each page is about.

Usefully, you can also use tags such as NOINDEX to stop search engines from indexing certain pages – do you really need your legal notices to be indexed and included in search engine results pages, for example? The default action of search engines is INDEX and FOLLOW (ie, follow all the links on a page) but you can also use NOINDEX and NOFOLLOW to control indexing of pages and linked pages. Ensuring that only relevant pages are indexed is all part of good search engine optimisation.

It may be that the role of meta tags isn’t either what it was or what it could be – but there’s still some advantage to paying attention to how they can be used.