Hospital's official stamp, with MD's sign is on the bottom of my last year HK Medical cert. 

Anything that looks official, preferably red. Remember those stamps that say "PAID", or "RECEIVED" and so on? Something like that. Not a postage stamp type of stamp. Or ask someone to sign it in red ink with flourishes. 

Not important. 9 in 10 times they make you do a Med check here, and half the time you'll pay for it anyway. It's a scam do make sure you don't have HIV before you get here. And your dear employee has to pay to 'repatriate' you.

The hospital or clinic's stamp is all you need. It doesn't have to be red, it can be black. Mine was black. As far as I know, it is important, and it's unlikely they'll accept it without one.

The first time, I did not need another medical check because I had the full checkup back home, and they accepted the documents without question. I had it done at a local clinic, not a hospital. However, I did get the chest xray from the hospital.

All of those documents were accepted without it.

Make sure the doctor puts the stamp over half of your picture, and half outside. That means the stamp must cover half of the picture, and half of anywhere else on the page, as long as the stamp connects.

never had that problem. my bs detector is going off.

In 10 years, never had this asked of me.

i am requesting of you to go to computer city and purchase a "completed" stamp

The government needs some official letter head on your physical like a stamp with a doctor's name and address.  If your doctor does not have one, just take your paper with the physical on it and put in the printer and put your doctor's information on it.

This happened to me two years ago as my doctor did my physical but did not have a rubber/stamp for her information on it.  So I did it myself with the printer.  Just red-tape.

First time I came here, brought a health certificate. No stamp then, and it was accepted. Ever since, I use the hospital that the school sends me to (school pays for it) and never had a problem.