Normally on the isle of quel'Danas when you complete the quest Know your lay lines the quest giver would inform you that you have a duplicate item in bag if you had retained the scroll from a previous time.However Today i was able to complete the quest and receive a duplicate of the teleport scroll
This being useful to get to shat from the eastern kingdoms or sandbag a scroll and you able to go to shatt from the isle twice perhaps if people are like me i do all the isle dailys and then the Ata'mal armaments, and Knowing your roots as a second trip this will let you return to shatt both trips