Anyone that has read the Harry Potter series knows that J.K Rowling doesn't actually use precise swear words in her books. She may say something along the lines of, "He swore loudly," or, "He said something that he wouldn't say anywhere else."
In Harry Potter and the Goblet of Fire, we have the following quote;
Ron told Malfoy to do something that Harry knew he would never have dared say in front of Mrs Weasley.
Has J.K ever explicitly stated what she means when she uses words or phrases like these?
Can we guess that Ron told Malfoy to go, "Fuck himself"? Is this overly extreme, or is this exactly what J.K Rowling was aiming for?
Please note that this is not suppose to be a limitless question, but a question about any real, hard evidence, about an interview about J.K Rowling or equivalent.