This is actually NOT allowed. "Virtual" discoveries will get that number locked in the system.
I'm going to remove all pictures that show the tracking number visible now. If you have a a picture with is blurred, please go ahead and update/post it (or send it to me so I can for you).
Edited to add: Please do not "quote" the images that show tracking numbers as it causes us more work to go back and edit all of those posts, too. Thanks.