The search system looks in any textual content we have for the cartoon. That includes the title, the official tags, the official transcript, the unofficial tags and the unofficial transcript. Not every cartoon has all of these, but every strip does have at least one of them.
Search works on whole words only, not substrings. Multiple words in the search are treated as an AND search - that is, all the words in the search need to match.
There's no point searching for very popular words, such as 'dilbert', 'dogbert' and 'boss' on their own as you'll hit the maximum number of allowable search results. But it can be useful to combine these with other, more narrowly defined search terms. For example, 'boss food' will work, and so will 'dogbert stupidity'.
Results are sorted in date order, from oldest to most recent strips.