The wink-wink urban legend.

In a report by Dr. James G. Salwitz dated February 6,2015 he writes The Line Between Comfort Care and Murder

"Do you mean that patients are deliberately killed by their physicians?"  Absolutely was the answer, confirmed by the nods of a nearly unanimous audience.

An older gentleman clarified "It's like wink-wink and then it's done."

...

Nonetheless for many mercy killing is part of the urban legend and is, wink-wink acceptable.  ....Are backroom medical murders really a ubiquitous dark secret?.

see http://www.kevinmd.com/blog/2015/02line-comfort-car-murder.html

Apparently, medical murders are done in nursing homes in British Columbia, I was told this by a registered nurse.  It is so routine that nurses don't even consider that it is murder, it is just done.

ubiquitous means existing everywhere
.