Which term does the AAMVA CDL Manual use interchangeably with "un-baffled" to describe a liquid cargo tank's construction?

49 CFR 383.119(c); AAMVA CDL Manual Section 8.2.5, "Un-baffled Tanks," p.8-8-2

Knowing that "un-baffled" and "smooth bore" refer to the same tank design helps a driver recognize the term either way it's used on the test or on the job, since both phrases describe the same surge-prone construction that demands extra care.