Hi bilofsky: yes, there is. And it seems that it was not clearly explianed in documentation before! (we missed it).
I've jsut added some information and screenshots:
Please, feel free to improve such documentation as you learn more about it, if you consider that your improvements will make the learning process easier for new people getting introduced in Trackers (or elsewhere in Tiki in general).
Cheers, and welcome to Tikiwiki Community!