Final answer:
The most common and least restrictive type of endorsement is the least restrictive means enforcement, which aims to limit freedom of expression in the least restrictive way to maintain public safety and order.
Step-by-step explanation:
The most common and least restrictive type of endorsement is the least restrictive means enforcement. This principle is part of the Constitutional law that requires any law or ordinance that limits freedom of expression to accomplish its goals in the least restrictive way possible. When applied to a situation such as managing public safety versus individual freedom of expression, instead of a complete ban on parades or marches, a city could use less restrictive measures, like limiting the time, duration, and requiring prior notice of such events. These measures would attain the objective of keeping streets safe and less congested without unduly infringing on the rights of individuals to express themselves.