Here are the steps necessary to create and apply categories or tags in NanoBlogger.
First to create a tag, use the following command:
nb tag new add
You will be prompted for the string associated with this cateogory or tag. Enter something like 'bash' or 'politics' (as appropriate) and the tag is created.
Then to list your current set of tags use:
nb tag-list
Each tag has a number and you use the number to assign tags to articles. Now find an article to apply your tag to - the way to do this is to list your current articles:
nb list
Then apply a given tag to a given entry. This is done using the numbers fro your list commands, so to apply tag 8 to entry 6, you would use this command:
nb tag 8 tag-entry 6
And if you want to apply several tags to one entry with a single command, you can comma separate the tag ids:
nb tag 4,6 tag-entry 1
A final nuance is apply tags to entries that are way back in time and therefore have entry ids above 10 (by default 'nb list' only provides access to the last 10 entries). In order to find and tag these entries, you can use the following commands, to find, tag, and rebuild your blog:
nb list query all | more nb query all tag 5 tag-entry 36 nb update query all
That, in a nutshell is tagging or categorizing with NanoBlogger.