When contributors enter a mblog, they can assign keyword tags to the mblog. Use this field to find the keyword tags a particular contributor tends to use when entering their mblogs.
To add keyword tags to your search, click the "Add" button. You will be able to type into a pop-up with autocomplete. That means as you type, it will display picklists of keyword tags that start with the letters you have typed so far. You should select from that list.
If you keep typing, you will come to a point where the autocomplete is no longer trying to help complete the keyword tag. That means you are typing a keyword tag that is not in our database. That is a good time to backspace delete characters until autocomplete does show you keyword tags. Otherwise, your will be searching for a keyword tag that doesn't exist and your search will yield no results.