Currently, I cannot seem to find a comparison tooltip addon for gear. For example... If I loot a new sword for my Warrior and I hold the cursor over the new item in my bag...I see a tooltip for the new item, but it is only for that item. I want it to show me the tooltip for the item I have equipped and the new one I just got. I know in BFA this can be done, but I have not found a way to do it in classic. To all you addon writers out there... thank you for making our WoW experience better.
You do it the same way in Classic as you do in BfA. You hold shift.
"You'd be surprised how many people violate this simple principle every day of their lives and try to fit square pegs into round holes, ignoring the clear reality that Things Are As They Are." -Benjamin Hoff, The Tao of Pooh