To respect the rules of another person's pack of gum. You take gum from the row that has already been taken from, not from a row that hasn't been touched yet. Everyone has their own rules for their respective gum packs.
Jay And T asked Bob for some gum when they saw that he had a pack. When he pulled out his pack of 5 Gum, instead of taking from the middle row that was already taken from, they decided to take from the right row, which had not been touched. They blatantly ignored gum pack etiquette.
by Chavez Jacques January 11, 2010