I know that mob tagging is already covered here in great detail. just wanted to share a new twist i have found, that will allow for person thats getting boosted to not be in group @ time of tag but still be in instance.
Came across this in Heroic VH SO i assume u have to use Heroics and raids because of ID.
So it works like this
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1. get group doing heroic or raid (u have to have fresh id for the day )
2. down first boss as group so it saves u to instance. ( u r now id'd for this instance )
3. everyone go out of instance.
4. person getting boosted gets invite
5. go back in
6. person getting boosted should now be id'd
7. go back out and kick person being boosted out of group.
8. go back in, the person not in group should now appear in instance not in group and can tag mobs without getting port to hearth.
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now as i said this worked on heroic VH we had issues with " instance being full " when our 5 party member was trying to enter when Id'd not in group toon was already zoned in..we did once have 5 more people in but it did hearth group peeps trying to enter .. I dont know how the loot will work or how xp/badges will be looted , we didn't get that far.
sorry if i didn't explain very well. i will try to explain the best i can if anyone doesn't understand. also sorry if this has already been discussed, i DID use the search Function and i didn't find anything.
Make sure u notice the color difference In there names Indicating the person that starts with P is not In Group party but still in Instance!!
edit:Removed the Word Theory to Better Suite some people
Edit : added some screenshots