The object balls (1-ball through 15-ball) are to be racked as tightly as possible in a triangular shape, with any stripe or solid at the apex of the triangle and on the foot spot, the 8-ball in the middle of the triangle, a striped ball in one corner of the rack and a solid ball in the other corner. The base of the rack should be parallel to the foot cushion.

8-ball Rack Diagram:

In a standard racking league if, after the balls have been racked, all balls in the rack are not in contact with one another, also known as a "loose rack", the shooter who is to break may request a re-rack. At which time the opposing shooter is to re-rack the balls so that all balls in the rack are properly contacting one another, also known as a "tight rack".

In a Rack Your Own league if, after the balls have been racked, all balls in the rack are not in contact with one another, also known as a "loose rack", the opponent who is not on the break may request a re-rack. At which time the shooter is to re-rack the balls so that all balls in the rack are properly contacting one another, also known as a "tight rack".

NO MORE THAN THREE RE-RACKS
No more than three re-racks should be allowed. If after three re-racks the balls are still not in a tight rack, a referee, a NAPA official or NAPA league operator should be summoned to perform the re-rack as best as possible and that re-rack must be the final re-rack. The NAPA league operator may assign a 3rd party to perform the final re-rack if needed. 

TIME ALLOTMENT
If a player takes longer than 90 seconds to rack the balls for their opponent (or themselves in a "rack your own league"), an initial warning must be issued.  Any violation of the 90 second rule afterwards is a concession of game.