I hear a summoned monster cannot in turn, summon another monster. So the argument goes, otherwise the world would get flooded with Nefarians and anyone summoning such a creature that could, but would prohibit it presuming the Nefarian is under the summoner's control and it would be folly to allow it.

I think its a rule somewhere, I just can't find it. Sometimes a Google search even shows it in the 3 line summaries for other rules systems, just not in the HackMaster 4.0 books.

For the sake of argument, let's use a devil:

e.g., The MM says such and such a devil can summon another type of such and such a devil with a 30% chance.

I've read the monster summoning spells I through VII, they all say the same thing and I did not find such a prohibition.

I read the GMG page 319, can't find it either. (Maybe it is my eyesight?)

Where is the rule?

I'm also thinking if a Nefarian was gated in, there is no such restriction, since there is no control by any Summoner.