I’m sure this is well documented somewhere, but I couldn’t for the life of me find it, so I thought I’d try to save someone some time and frustration.
Most people have probably used a WebDav URL to reference a Tridion object sometime in the course of their development. WebDav URLs are usually of the format:
/webdav/030C Account Center Content/Building Blocks/Content
So, if you wanted to reference the “Content Icons” category, you might expect to use the WebDav:
/webdav/030C Account Center Content/Categories and Keywords/Content Icons
This, however, is not the case. To reference a category you need to skip the “Categories and Keywords” structure. So, your WebDav would be:
/webdav/030C Account Center Content/Content Icons
This is because each category is a “root organizational item” itself, meaning that it doesn’t make sense to have “Categories and Keywords” as the root of a root if you will. This is different from the folder in the above example and most Tridion items we are accustomed to. Root organizational items have their own rules, and this is just one example.