What is the 'snub braking' technique used to control vehicle speed on a long mountain descent?

AAMVA CDL Manual (nhcdm.pdf) Section 2.16.4, p. 2-32 describes this on/off brake-application technique for controlling speed on a long descent, though a full-text search confirms the manual itself does not use the term 'snub braking' — that is standard tr

This on/off braking technique is what allows a driver's brakes to survive a multi-mile descent without overheating. Drivers who ride the brakes continuously instead often experience fade within 3 to 5 miles, which on a steep, long grade can mean losing stopping power with no way to recover.