Videos from around the web on the finer points of tuckpointing.
Tuckpointing is another way of saying that you are replacing old mortar with new mortar. The crumbling mortar is ground out to a certain depth and replaced with new. It can also be a way of using two contrasting colours of mortar in the mortar joints of brickwork, one colour matching the bricks themselves, to give an artificial impression that very fine joints have been made.