Many web designers I talk with are still confused about which Meta Tags they should include in their code. While it is acceptable knowledge among SEOs that the Meta Description tag is somewhat useful and the Meta Keywords tag is very rarely used, most designers don’t realize the majority of all meta tags are absolutely useless for SEO purposes.
That’s right, useless. But wait, I want to use the revisiter-after meta tag to tell Google to come back to my site for new content everyday! Useless. I want to use the meta keyword tag to identify popular keywords I want to rank for! Useless (Some of the less popular search engines still don’t exclude the meta keyword tag, but I (and others) doubt it is ever used as a factor in ranking content for SERPs).
So what meta tags can you use? The meta description tag is still useful, because even google will display this content under a page name in the SERPs if it can’t find a worthwhile snippet of code on the page to display.
META NAME="description" CONTENT="value"
If you’ve created a good description, it could entice visitors to click on your link. It is important to note that descriptions should be unique to each page on your site, highly relevant to the content on each page, and of high quality. “This is my web page about SEO” is much less desirable than “Barry Wise, June 11 2008, debates the effectiveness of HTML Meta Tags used in Search Engine Optimization practices.” Google points out that the description doesn’t have to be in sentence form, it can contain any relevant, structured data about the page, such as name, date of publication, price, age, manufacturer, etc., and any and all important data depending on the content of the page.
And what about that meta keyword tag?
META NAME="keywords" CONTENT="value"
So many people used it to spam the search engines back in the 90s, that it’s pretty much useless now. Some argue that it’s actually detrimental to your cause, since it exposes your primary target keyword research to your competitors (wait … you are doing keyword research, aren’t you?) The general consensus is that even if search engines (maybe only Yahoo?) still look at the tag, they’re probably not using it to calculate where your page will rank. So should you use it? While it may be useless, it probably isn’t going to hurt your site, so it pretty much remains up to you. Do I use it? Yeah, so what … wanna fight about it?
There are some other slightly useful meta tags out there, such as the ROBOTS tag.
META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW"
This can be used, to a small extent, to help control how search engine spiders are crawling your page and describing its contents:
NOINDEX tag tells a search engine not to index a specific page
NOFOLLOW tag tells a search engine not to follow the links on a specific page.
NOARCHIVE tag tells a search engine not to store a cached copy of your page.
NOSNIPPET tag tells Google not to show a snippet (description) under your a search engine listing, it will also not show a cached link in the search results
It should be noted, however, that to prevent indexing of pages you’d be better off using the robots.txt file, and to make certain links nofollow to increase internal link power.
So what is a useless ROBOTS tag?
META NAME="ROBOTS" CONTENT="INDEX, FOLLOW"
Google (and any other search engine I know of) is going to crawl your site by default if they have your URL. Explicitly telling them to INDEX or FOLLOW isn’t going to increase your chances of getting indexed, so don’t do it. It just might piss them off.
In the event that you have an older website which already has a description in the Yahoo Directory (NOYDIR) or the Open Directory Project (NOODP), and you don’t want this snippet or description displaying in the SERPs, you’ve got a couple options:
META NAME="ROBOTS" CONTENT="NOODP"Webmasters can decide if they want to disallow the use of their ODP listing on a per search engine basis:
META NAME="GOOGLEBOT" CONTENT="NOODP"
META NAME="Slurp" CONTENT="NOODP"
MSN and Live Search:
META NAME="msnbot" CONTENT="NOODP"
And specifically to avoid the use of the Yahoo Directory description in Yahoo:
META NAME="ROBOTS" CONTENT="NOYDIR"Source
META NAME="Slurp" CONTENT="NOYDIR"
(FYI, Slurp is Yahoo’s web crawler)
There are plenty of other meta tags out there, such as GENERATOR, PUBLISHER, REVISIT-AFTER, EXPIRES, etc., and they all may serve some purpose if someone looks at your code, but they are all equally useless in the eyes of the search engines for the purposes of search engine optimization. You can tell Google to REVISIT-AFTER: 1 hour but it’s just going to fall on deaf ears. They simply don’t use that tag.
So what tags do I use? I always create a unique DESCRIPTION for each page and I do still throw a few keywords in the KEYWORDS tag (just in case we’re all wrong about that one). I do use the AUTHOR attribute for pages I design, but only to let other humans know who designed and programmed the site in case they review the code. Not once has that author tag ever been picked up by a search engine.