Helping search engines identify what a blog post is about via tags

Question

I was thinking about implementing a tagging system for my blog to attach one to five tags to each blog post.

Are there any tricks to help search engines identify that these are tags though and that they should use this information to help determine what the blog post is about?

Or is tagging completely ignored and not given any extra weight from other text on your web page to a search engine?

Answer 1

I definitely recommend using the rel="tag" microformat attribute.

http://microformats.org/wiki/rel-tag

I have mixed feelings about microformats in general but this one is quite easy and simple, and has no downside.

You can see how we do it in our engine right here, for this very question, tagged [seo] and [tags]

<a href="/questions/tagged/seo" class=".." title=".." rel="tag">
<a href="/questions/tagged/tags" class=".." title=".." rel="tag">

Answer 2

I've found that strategic use of nofollow links helps here. For instance, tags at the bottom of the post should not be followed, but the link to the page that shows all posts in that tag should be. Then create a 'tags' page that leads to those pages. Additionally, use nofollow links in your tag cloud, should you have one.

What you need to be careful of is not duplicating this with category / archive links. If tags are the way to find your posts, use tags strictly.

Also, keep in mind, the goal is ~100 links or less on any given page. That's sometimes impossible, especially with a blog .. but less is more regardless when it comes to links.

Answer 3

There's not a standard way to do this, but here are some options:

1. A <meta> keywords tag:

   <meta name="keywords" content="tag1, tag2, tag3" />

2. Link each tag to a master page, each of these has a list of like-tagged posts:

   <a href="http://blog.example.com/archive/tag/tag1">tag1</a>

   <a href="http://blog.example.com/archive/tag/tag2">tag2</a>

   <a href="http://blog.example.com/archive/tag/tag3">tag3</a>

3. And there's something flickr uses, the attribute is data-ywa-name, which appears to be related to an IEC-11179 metadata registry. How to set this up I'm not sure.

   <a href="http://blog.example.com/archive/tag/tag1" data-ywa-name="Tag(s), Global">tag1</a>

   <a href="http://blog.example.com/archive/tag/tag2" data-ywa-name="Tag(s), Global">tag2</a>

   <a href="http://blog.example.com/archive/tag/tag3" data-ywa-name="Tag(s), Global">tag3</a>

4. Now, there's an HTML5 Microdata specification in development, their spec does not include something specific for tags, but here's a stab at how one might mark up tags that are not linked:

   <p itemscope>

   <span itemprop="tag">tag1</span>

   <span itemprop="tag">tag2</span>

   <span itemprop="tag">tag3</span>

   </p>

1. seems likely to be useful for search engines which use the keywords meta tag. And 2. could useful to your visitors. 3. and 4. seem like they could be useful though I'm not sure what search engines might use them.