[NTG-context] Conditional keep-with-next rules

Dear All, in my index I can see disturbing page breaks. primary-01 primary-02 secondary-01 ------- ( next page ) ----- secondary-02 primary-03 instead of primary-01 ------- ( next page ) ----- primary-02 secondary-01 secondary-02 primary-03 Is it possible to somehow define conditional keep-with-next rules? I'd like to express: (1) keep always the primary with the first secondary (this seems to be implemented) (2) keep always the first secondary with the next secondary (3) keep always the last secondary with the previous secondary And similarly for tertiary. As the Index is generated, I can't see an easy way to accomplish something like this. I hope I am wrong :-) Thanks, Jan