It gets hard to keep track of all your different rats! The tagger can help. It allows you, the user, to assign tags much like the labels in gmail, to rats or to individual sessions.
A rat tag can be used to keep track of what experiment your rats are in. But they are richer than that!
Rat tags are dated. Not based on the date that the tag was assigned, but rather a specified date, generally the sessiondate of the associated session. A rat tag is valid from the tagdate into the future until that tag is removed using subtag.
Let's say your rat starts losing weight. You can tag the rat underweight when the rat starts losing weight and then remove that tag once the problem is fixed. The underweight tag will be valid between the add tagdate and the remove tagdate.
Session tags are not dated per se, but they are specific to a specific session. You can automatically tag sessions from end of day logic if your protocol uses this plugin. For example, if you find that your rat is totally biased for a day you can add the tag biased to the session. If no pokes are registered on the left you could tag the session poke busted. This way you can use the tags later to decide whether sessions should be excluded from analyses.