I've read this part of the WiKi:
http://www.hard-light.net/wiki/index.php/Intersystem_jump_driveIt's confusing and should be changed.
It explains intersystem subspace jumps like something that goes within a system. It's not correct.
INTER- means "BETWEEN TWO (or more) ..."
Interplanetary = between planets
Interstellar = between stars
International = between nations
So intersystem means "between two systems".
The explanation talks about INTRAsystem in fact.
Then it says ships can manouver and track each other in subspace during "intersystem" jumps, as Terran ships tracked the SD Lucifer before it jumped to Earth.
Now this was in subspace between two stars, so it was indeed "intersystem".
It should be clarified.