HTML and CSS Reference
ments such as frames and layers are generally not supported, and lim-
ited table support makes table-based layout difficult as well. In general,
view the mobile device as a simple vertical flow of content and allow the
mobile browser to format your content as best it can without your inter-
Finally, be aware that adaptation may occur with your content. Adapta-
tion is the automated conversion of your content to make it more suit-
able for a mobile client. It may occur at the server, when a mobile device
is found to be requesting a page. It often occurs within the carrier net-
works, where pages are stripped of offending tags and images are dra-
matically reduced to make them more acceptable to the mobile device.
It also occurs implicitly in the mobile browser, where unsupported tags
and attributes are ignored during rendering.
You cannot prevent adaptation. Your best bet is to avoid it by creating
simple content that will not be subjected to adaptation at any layer. In
short, the simpler that your content is, the more likely it is going to ap-
pear as intended on the mobile device.
In the early days of the Web, images made life difficult. Dial-up con-
nections just weren't able to deliver large images in a timely fashion,
leading to user frustration and unusable pages. Older web users may re-
member the days when links often had parenthetical sizes appended to
them. When running on a 28.8 kilobit modem, selecting a link followed
by "(132K)" gave you time to grab a coffee while the image made its
way to your browser.
Fabulous advances in cheap bandwidth have made an image-rich web
experience the norm. Designers are used to using large images to make
their pages beautiful. Unfortunately, these kinds of designs fail on slow
mobile devices, as well as fast mobile devices with limited memory. As
a result, images, especially large images, are a luxury in a mobile envir-