When you create or edit a session you can tag the session with any number of words or numbers. This will be come useful later when filtering your training and testing data.
A really go way to start is simply to tag all your test sessions as such, it will help you filter through the data later on.
Where can use the Tags
You can use tags on almost every page where you have training information.
Calendar - simply type the tag into the filter on the left hand side and all sessions without that tag will disappear.
Reports - same as in Calendar, simply type in your results and see how the data shows only your test sessions.