Glossary
Harmful means if something has a significant impact.
For example, the Road Traffic Ordinance on the use of mobile phones while driving states that "When driving on the road with a motorized vehicle, the driver may engage in activities such as the use of a mobile phone and other communication equipment, only if it does not adversely affect the driving of the vehicle."
In this example, "has a detrimental effect" simply means that the driver of the vehicle is not allowed to use a mobile phone or other communication equipment in a way that makes him an inattentive and dangerous driver.
