Hi Paul, Typikon 100 is brand-new this year, which is why it’s probably not in the catalogue.
Typikon 101 basically assumes that you are familiar with the fixed parts of Vespers, Matins and the Liturgy. We were finding that some people didn’t have that down, so we created Typikon 100 as a way to focus on the structures of the services, before we delved too deep into all the variations of the moveable portions.