Problem about external css

Question

for using link tag to add the address of .css file in head, i should put "/" in the last part of link or not?
is it necessary?
1. <link rel="stylesheet" href="...">
2. <link rel="stylesheet" href="..."/>

Answer 1

In Html5, the ending slash isn't valid: self closing tags ( ie. <br> <hr> <img> <css> and so on... are always empty tags ), only require the ending slash with XHtml branch ( based on more strict XML, than SGML for classic branch -- XHtml was abandonned with Html5 ). Browers support it for ascending compatibility ( and bad habits ), but Html validator don't accept ^^ Good practice to keep the usual to avoid them...