Originally Posted by monojohnny
Thanks for the correction, indeed it is : \r\n as you said ..
The characters and order dates back to before bidirectional printing. It takes longer to send the print head back to the beginning of the line than it does to move the paper one line down. Therefore, you need to send the commands in this order to speed up the printing. Sending the return by itself was used to support overprinting, underlining, etc.
Of course on an electronic screen you really don't need both characters so some systems drop one or the other. Macs used to use only the \r while Unix uses only the \n. I am not sure what OS X does these days. PC's keep them both but some programs can get confused it they don't see both of them in the correct order.