I am not talking about uneducated laborers, either.

improperly or by untrained personnel can be dangerous!

DO NOT allow untrained personnel to service this equipment.

Operating machines is forbidden by untrained personnel.

improperly or by untrained personnel can be dangerous.

Unauthorized personnel must not operate the machinery.

NEVER allow untrained personnel to operate or service the generator.

NEVER allow untrained personnel to operate or service the generator.

After all you don’t hire untrained trainers, right?

Allow untrained personnel to handle, store, mount or use abrasive products.

Leaving this sensitive subject to untrained staff can backfire.

Staff untrained in conducting investigations or on the legislation they enforce;

Kyle Andeer says that a repair done by untrained personnel can cause risks.

The use of family members and non-trained staff for translation is discouraged.

The US has ordered all non-emergency personnel to leave Libya