Now we have tracking in two senses of the word! I'd like to add definitions.
Tracking can be what bomber noticeably do, they return to a refuel pad and set out in the right direction even if the target is not in radar or LOS. All units track, it's an engine thing.
Homing is what certain missiles do that makes them unable to miss their target (if missile fuel doesn't run out). If a target leaves LOS and radar the missile will stop homing.
Anyway EMP missile Homes, which Godde said before Luckywaldo introduced ambiguity in terminology. They have had the tag for a very long time yet it used to not do anything at all. Maybe an engine change or some other recent change has caused the tag to be used. Anyway I don't think it should home as it does EMP absolutely everything and not hitting mobiles is suppose to be it's disadvantage.
"Rember that OTA trick where you had a unit (cheap like a weasel ie) guard a solar, and then shift queued an attack on the enemy commander as soon as you saw it.
You could tell the position of the enemy commander from there on by holding shift and selecting the weasel. Because the attack order would still work outside of LOS. :-)
Can we now do this again with 0K?"
This exists to some extent. The attack command exists but is not drawn on units outside of LOS and Radar. So you cannot pinpoint a commander outside of LOS and Radar but if you lose radar and regain it the attack command will point to the now "unidentified" radar dot.