Procmail presorting (e.g. assign to group)

Hello,
I would like to assign a group to an incoming mail with procmail. In the docs I found an example of .procmailrc and it is stated that you can presort to a group but there is no example and I could not find any other documentation on how to do this.

So my question would be: how can I presort to a group with procmail and is there a complete command reference where I can see what is possible?

Edit: I found a reference for the header manipulation here.

Thanks and best regards