No Further Requirements, in relation to “green in between” and “target resolution” you state:
Under what circumstances are these procedures used and what is the standard? Between which categories of aircraft?
Looking at the document produced by CASA called “Provision of reduced separation minima between VFR and IFR aircraft”, it appears that in the USA, in Class C airspace there are no limitations for target resolution in relation to the aircraft category.
For Class B, target resolution can be used for “aircraft which weigh 19,000 pounds or less.” It says later (re Class B) that aircraft “which weigh more than 19,000 pounds and turbojets” are separated by 1.5 miles of lateral separation, or 500 feet vertical separation, or visual separation.