What Does a Tag Mean?

When I'm assigning a tag to something (on flickr or del.icio.us), or even earlier when I'm thinking about what tag to use, I'm asking myself some of these questions:

1. What is this thing?


2. What is it about?


3. Who is the writer or owner of this thing?


4. Does it go into one of my special categories (first, ideas, toread)?


5. What tags did others use for the same thing?


6. If this is an index of other resources, what does it contain (articles, blogs)?


7. If I want to find it later, what would I be looking for?


8. What else is it like, and how did I tag those things?


9. What category does it belong to, what type of thing is it, how would I classify it?

One problem is that until now, I didn't have this list handy, so my tags are inconsistent in meaning. I'm usually good about asking myself the first 4 questions (Note to self: there's something familiar about 4 questions...), and del.icio.us makes #5 easy by suggesting other tags, but the others are harder to remember. So maybe this list will help me gel my tags. But maybe the questions are in a descending order of meaning to me.

Another problem is that my intentions frequently collide and the same tag has multiple meanings. For example, I used the tag 'webapps' on an article about web applications, a list of webapps, and an actual web application. On further review, the actual web application isn't about webapps, it is a webapp, and aboutness is far more meaningful to me than classification. But maybe I used 'webapps' because that tag was in a list and I just selected it because it was close enough. After the fact, I want to separate the article and directory from an example.

One way to handle that is to give my tags some sort of tag. I like the way that del.icio.us indicates that you are tagging something for someone else, with the for: prefix and their id. That's very much like a namespace, and perhaps that the model to follow. So, I could start using about: to prefix tags that indicate aboutness, writer: or author: or owner: or by: to indicate the person or company who runs the thing, is: to indicate what it is, etc. In my case, I might consider about: to be the default namespace for my tags, and other types of tags would need a prefix. Then what would I do about a self-referential blog that's both about and by the same person or company.

So now there's another meme about machine tags, that are in the form of namespace:name=value. They look like a simple form of RDF but they're not quite the same thing. They seem to be a natural for geocoding, and the examples on flickr are just that. This idea might be too much for my immediate needs, but have some interesting possibilities as a format for post hoc metadata.