Code of Maryland Regulations Title 03 — Comptroller
COMAR 03.03.03.16 — § 16 Loading of Conveyances.
.16 Loading of Conveyances.
Whenever the operator of a petroleum transporter conveyance is intending to load a different grade or type of motor fuel than was previously contained in a pot, compartment, or hold, the operator shall first ensure complete drainage before loading.
Source: official text