Arriving late is strongly discouraged, as it will disturb others and you will miss the instructions read at the start of the exam. In the event that you are delayed, you will be admitted up to thirty minutes after the starting time. You will not receive extra time if you arrive late. It would make the administration of the exam too complex. It would also raise confidentiality and security issues.
Smoking is discouraged, but sometimes permitted, depending on the location.
There is no dress code to participate in the exam. However, some exam rooms might be rather cool or warm. Should you bring any of these items, you will be required to leave them in another room. I was convoked to take last year's exam, but I did not take it. I took the last national exam in February.