I was going through some legacy code (circa 2010) and discovered a <css> tag in .css file. Code looks something like that:

// styles.css
<css>
body {font-family:arial; font-size:12px; margin:0; }
td {font-family:arial; font-size:12px;}
.stroke {background:#CCCCCC;}
[.......]
</css>

As I understand, this css file is non-legitimate and not to standard. At least, <css> or for that matter any other tags should not be present in .css files.

I couldn't find any <css> tags in W3C or any such tag mentioned in google's searching. Is it some legacy (6+ years) thing or just a mistake of the original developer?