✔ 最佳答案
Nothing relaqted to 人權/勞工法. The dress code is the requirement an employer wishes to established. For example, A front line staff of a bank reception should dress in a subdue colour suite or in uniform to make herself/himself looks professional. This is a way a bank has to established to build up the good image and trust with the customers. This is also the condition of employment of being employed as a customer receptionist.
As this is a condition stated in employment contract binding each parties, so a person can accept the terms stated before he/she is being employed. An offer and acceptance.