Do i need to specify CSS for media="handheld" and use of CSS media queries if I'm making a simple mobile site for iphone, android, blackberry only?

Do i need to specify CSS for media="handheld" and use of CSS media queries media="only screen and (max-device-width:xxxpx)" if I'm making a simple mobile site for iph开发者_如何学编程one, android, blackberry only?

Or media="all" or media="screen" would be enough?

I'm only targeting Blackberry 4.6+, iphone and android.

It depends on what kind of devices/browsers are you targeting at. For example s60 browsers behave differently than iPhone, Android, Opera mini and similar browsers. Here is a nice article for your learning pleasures. http://www.alistapart.com/articles/return-of-the-mobile-stylesheet

iPhone and Android don’t load media="handheld" stylesheets.