Quote
"Any restrictions imposed on assemblies must have a formal basis in law and be based on one or more of the legitimate grounds prescribed by relevant international and regional human rights instruments: national security, public safety, public order, the protection of public health or morals, and the protection of the rights and freedoms of others."
Cite
Document
OSCE (ODIHR), CoE (Venice Commission): Guidelines on Freedom of Peaceful Assembly (Third Edition), para. 28