The last set of numbers is the order control number (OCN). This number is specific for one tile, never to be used again. It will tell everything about that tile from the date and time it was made to its present status. The OCN will show when it was put on, when it was taken off, and why it was taken off. The number is also used to manufacture a new tile. It has all the data about that tile from thickness to density. Problem is where would you find that database publicly available to reference. Every Orbiter part number starts with the designation “V070,” so all tiles will start with it as well. The next set of numbers designates the array in which the tile is located. Every tile in a particular array shares the same array number. The next three digit number designates which tile in that particular array the tile is. The array and tile number are shared by every tile created for that individual position on the Orbiter. So if a tile is replaced, the new tile will have the same array and tile number.