仰本身，根据《公民及政治权利国际公约》第十八条第三款，限制必须是由法律规定、明确必要(即作为最后手段)、追求正当目标、相称(即干预程度最低)，并在意图和效力上不歧视。
and, under article 18 (3) of the International Covenant on Civil and Political Rights, they must be legally prescribed, be clearly necessary (i.e., as a last resort), pursue a legitimate aim and be proportionate (i.e., minimal degree of interference) and non-discriminatory in intention and effect.