@gizard
my best guess is the version of iress pro provided to the end user is customizable to that clients needs. just as Boeing make the same 787's and adjust seating and other designs to their customers needs, then so do iress. one brokers version may be customized and do things anothers won't.
in any case, the BIG problem with all this propriety software stuff, is they just do not give out any technical information any more. Stopped giving technical stuff out in way back in the late 70's/80's when commercialism took over from being decent.Thats technical info, user info is just as bad. No company these days has the time or staff to explain how to use stuff, so you are left to your own abilities to figure it out, or join hopeless user forums.
thats why no-one knows.....................
my best guess.