The current HTML5 specification recommends specifying size icons in multiple sizes using the attributes
rel="icon" sizes="space-separated list of icon dimensions" within a
<link> tag. Multiple icon formats, including container formats such as Microsoft .ico and Macintosh .icns files, as well as Scalable Vector Graphics may be provided by including the icon's content type in the form of
type="file content-type" within the
Apple mobile devices running iOS 5 and above ignore the HTML5 recommendation and use the proprietary
apple-touch-icon method detailed above. The Google Chrome web browser however, will select the closest matching size from those provided in the HTML headers to create 128×128 pixel application icons when the user chooses the Create application shortcuts... from the "Tools" menu.