A man in Miami took extra care to make sure his end-of-life medical treatment went according to his wishes: He had the words “do not resuscitate” tattooed on his chest.

The black, bold capital letters were in plain sight on his collarbone. The word “not” was underlined, for good measure. And the man’s own signature was reproduced beneath the demand.

It worked, in a way. The man, 70, had a history of lung disease, heart problems and diabetes when he was admitted to the Jackson Memorial Hospital this year. He was unconscious and did not have any identification. His blood alcohol level was high.

According to a letter published in The New England Journal of Medicine on Thursday, doctors administered some treatment, but the man never became responsive enough to speak. And while the message of the tattoo was clear, doctors had no way of knowing whether getting it had been an impulsive decision.