to add to tester, i would check if there are possiblities for linebraks in that line at all, you'll need spaces for it and there should be not which will prevent browsers to linebreak at this special character.
it is the pre setting. pre stands for pre-formatting. this is useable if you want to list source or texts on a website and you don't want to set the breaks. it's like the good old <pre> tag in html. since version 1 of html i guess.