Dose volumes can vary down to five times pipe void capacity. There is a minimum head pressure required at the distal end and it varies with hole size. Laterals can be down to three-quarters of an inch. Hole size can be down to one-eighth inch. The number of holes depends on the size of the absorption area.
Laterals can have a very slight pitch for draining.
The old code required laterals be level. Cleanouts must be supplied on all laterals. The old code did not require cleanouts. The main difference is that the lettering be at least one-half inch in height and be either indented or raised. The label shall be rectangular in shape with minimum dimensions of 4 by 5 inches.