A...ahem...friend of mine contracted one of these ailments. He made an appointment at the STD clinic at the local hospital. Only when he turned up did he realise that he didn't know where abouts the STD clinic was. In fact the hospital is split over several sites, so it was possible he was not even in the correct building.
Anyway, he confidently strode up to the enquiries desk. An elderly gentleman was performing the role of receptionist.
"Hello", said my friend. Let's call him Dennings.
"Hullo", said the old gentleman in a far back and aristocratic accent.
"Can you direct me to the STD clinic?" Denings whispered, trying to keep his voice down, as there was an electrician working on the fire alarm system not far behind the elderly gentleman.
"THE WHAT?" said the elderly gentleman cupping his hand to his ear.
"The STD clinic?" said Dennings still quietly.
"STD!" yelled the elderly gentleman confused.
The electrician dropped his scredriver and coughed as though stifling a laugh.
"Yes." Said Dennings "It stands for sexually transmitted disease."
"OH. I THOUGHT YOU MEANT STANDARD. I WAS THINKING...STANDARD...STANDARD...WE DONT HAVE A STANDARD CLINIC." he laughed loudly, "YOU WANT GENITO-URINARY. That way."
The electrician had left the room by now, unble to control his coughing. And a queue which had formed behind Dennings all appeared to have caught the cough, as Dennings dejectedly walked past, head bowed.