What are the rules behind Success.clarizen.com's Search feature?

Do you have a specific example?

Two specific problems:

1. If I enter two words in the search bar, I get what appears to be the union of the two sets instead of the intersection of the two sets. (For example: "calendar" returns 292 results, "PTO returns 42 results, and "calendar PTO" returns 310 results.) I'd like to get the intersection (containing both calendar and PTO), but I've tried various things ("calendar AND PTO", "calendar+PTO, etc.) and don't get the results I would expect from a standard search engine. (In this case, I'd expect the number to be less than or equal to 42.) So, that's why I asked whether you had a how-to guide that would explain the rules for using this particular search feature.

2. Sometimes I get items in search results that don't contain the terms I entered in the search box. I can't remember the specific searches I ran last week when this happened, but I'll report what I find in this thread next time it happens.

I don't believe advanced operators such at + or wildcards are available in the search yet, it will pull from the most complete match first then search for content using any of the words in the query. The more words that match, the higher it should be on the results.