When dealing with a wiki, longevity is key! I've made that point already, but I'll continue reiterating it so that it is sure to sink in. Each page you create in the short term is another step down the long term road. As your wiki grows, you need to make sure that it doesn't fall short in: content quality, content accuracy, and content organization. One might even call those the three Cs of a wiki – perhaps I will at a later date.
So clearly, one of our primary objectives is to keep a wiki maintainable, so that we can provide it with longevity. One of the simplest ways of keeping a wiki maintainable is making everything organized and easy to find. Nothing can truly be "lost" (as in, become unable to be found), because you can always find uncategorized pages. However, when a wiki user is caught up in the moment, it can be quite easy to get lost or find difficulty in locating certain pages or content.
When designing your wiki, you were advised to think about the following question:
- What categories will be derived from the wiki's overall subject matter?
In short, this means that you would've identified the overall topic of the wiki, and then would've derived from it, certain categories to be used for organizing sections (no matter how large or small) and pages of the wiki.
Different wiki software has different markup, but in MediaWiki you can very easily categorize a page by appending the following to it:
[[Category: Name of the Category]]
I recommend prepending this to the top, or appending it to the bottom of the article's wiki code. Depending on your theme, the category will be shown at the top or bottom of the page once saved, but that will happen regardless of where the categories are positioned in the wiki markup, so it's more sensible to put them at the top or bottom so that they're out of the way of everything else and not scattered about randomly.
The result on the page would look something like this:
You can add as many categories as you would like, as follows:
[[Category: Mercedes-Benz]] [[Category: M-Class]] [[Category: M 2010]]
The result will be:
Categorization is perhaps one of the most important initial steps towards properly organizing pages on your wiki, and it's so simple that there's never a reason not to do it. Keep in mind that those categories will show up red until they are clicked on and a page is created to explain a given category. However, they will function properly even if you never create the category pages for them.