The phrase "a certain courtesy" is correct and usable in written English.
It can be used to refer to a specific type of politeness or consideration in a given context.
Example: "In our interactions, we should always extend a certain courtesy to our colleagues, regardless of our differences."
Alternatives: "a particular politeness" or "a specific respect".
It isn't always clear exactly what Murdoch believes on any given issue, but this time we know for certain, courtesy of an interview in the Australian magazine, the Bulletin (which, by the way, he doesn't own).
He did not go out of his way to defeat someone in argument; instead he tried, always with a certain decorous courtesy, to try to persuade, to reframe his interlocutor's view, to signal his understanding while disagreeing.
Of course, certain courtesies are extended to a donor at Mr. Bloomberg's level.
I'm a shuttle driver and people like me, we spend so much time in cars, there are certain courtesies we should be able to have.
There are still 48 Democratic or Democratic-leaning senators in the upper chamber, and traditionally the Senate Judiciary Committee extends certain courtesies to home-state senators whenever there are open seats in their states.
"Even the most forthright of us have to have a certain reserve, a certain respect, courtesy and understanding that you're dealing with politics and not theology," said Robert E. White, president of the Center for International Policy and a former ambassador to El Salvador.
On Sunday, the name of Kim Jong-un's baby became known almost by accident, courtesy of a certain former US basketball star who keeps popping up in Pyongyang.
The rule should help boys and girls learn to treat each other with respect, courtesy and a certain icy distance.
It is often larded with a thick layer of moral hectoring, courtesy of a certain variety of the American Right which seems to think that economics is its exclusive property, a stick given it by God to beat liberals with.
Decorum, courtesy, kindness and a certain self-deprecating humor were the most comfortable way to open doors, keep them open and protect from the ill will of anyone lurking behind them.
