A court or agency cannot hide, change, or wipe out a commercial driver's traffic conviction just to keep it off the driver's CDL record.

"Masking" means making a violation disappear in name while the underlying conduct stays the same - for example, amending a moving violation to a non-moving one, using a diversion deal, or deferring judgment so the conviction does not reach the commercial driving record. The "prohibition" means states are not allowed to do that for CDL holders when the purpose or effect is to avoid the licensing consequences required by law. The rule comes from federal regulations, especially 49 C.F.R. § 384.226, and Wisconsin must follow it through its CDL system run by the Wisconsin Department of Transportation.

Practically, this matters because a CDL holder can face real penalties for convictions that might be negotiable for other drivers, including disqualification, points, and a worse safety history. On heavily traveled Wisconsin routes like I-94 between Milwaukee and Madison or I-43 in winter weather, that record can affect whether a driver keeps working.

In an injury claim, the rule can matter because a truck driver's true violation history is less likely to be cleaned up through plea bargains or diversion. That can affect evidence of negligence, negligent hiring, or negligent retention if a crash involves a commercial vehicle and the employer knew, or should have known, about a risky driving record.