Is that supposed to be very complex legal language? I'm not sure if this is some reference I'm missing, but it sounds relatively simple to me: it seems to be an accusation that someone is providing services dis-honestly (i.e. hiding some aspect of how the service will be performed or how much it will cost).

The full scope of what that encompasses is very hard to know, as it depends on essentially every other regulation and common law practice and precedent that applies in the particular legal jurisdiction (and which jurisdiction that is can itself be a somewhat thorny issue).

But this problem isn't solvable by code. It's part of the intrinsic complexity of the legal system.

Whatever statute you're looking at likely defines "intangible right of honest services" and "defrauding."