Registered: 14 years ago
It all depends which version of PHP you will be working with in future - so its good to know about both. <br/> or \n is indeed a preference decision. It won't impact the code - you can echo any html tags. I'm used to <br/> so I use it.
You are correct, using $_GET, $_POST, $_REQUEST variables, and SESSION variables instead of globals is the way to go, the other options are becoming more and more obsolete.
Also, don't assume <br> and \n do the same thing, they don't. <br> is an html tag, \n is has nothing to do with html, but is actually an ASCII command for linefeed. In fact, linefeed usually occurs after a carriage return command, i.e. \r\n (carriage return - linefeed).
The only reason you would want to use it, is if you wanted your "view source" code to look nicely formatted, or if it were a requirement of a dynamically generated file export.
So, you will need to stick to the html tag <br> if you require a linebreak in your web page, and you can add \n or \r\n if you want your "view source" code to look nice, but they are not the same thing. As you suggested in your original post, use both and you won't go wrong.