Using the Right Tag for the Right Job - HTML5 Mastery: Semantics, Standards, and Styling - page 51

SCRIPT: AT THE TOP OR AT THE BOTTOM?
It is important to note that the script and style elements do not need to appear in
the head of the HTML document; in fact, the Yahoo! Developer Network published a
list of 35 best practices for performance gains that stated the script element should
be placed at the bottom of the web page (see http://developer.yahoo.com/
performance/rules.html ) . (Conversely, the style element should appear
at the top, in the head area.) Additionally, the HTML5 Boilerplate ( ht-
tp://html5boilerplate.com ) mentioned in Chapter 1 places all scripts (ex-
cept Modernizr, because it is needed earlier) at the bottom of the page, before the
closing </body> tag. Arguably this practice, while offering a performance boost,
has semantic issues, because it moves metadata about a page into the body area, in-
stead of the head where it belongs. Ideally as the async and defer attributes gain
wider support, the location of the script element within a page will become a moot
point.
Lastly, the noscript element is for surrounding content that is shown only when
scripting is disabled or not supported in the browser. If the noscript element is placed
in the head of the document, it can contain only the link , style , and meta elements;
otherwise, if it is in the body, it can contain all the normal elements that would appear
in the body element, except another noscript element. It's also worth noting that the