[whatwg] Lowercase attribute values

[Henri Sivonen]

In XHTML there are attributes whose value must be in lowercase, 
although in HTML the value is case-insensitive. The most common example 
is the method attribute of the form element. But should rev and rel be 
lowercased?

A piece of software that maps from the HTML flavor of HTML5 to the 
XHTML flavor and needs to decide which attribute values to lowercase. 
How should the decision be done? Based solely on the attribute name? 
(In which case 'type' would be interesting.) Based on both the element 
name and the attribute name? What is the recommended method for the 
author of such a piece of software for extracting the list of special 
cases from the spec?

How should the lowercasing be performed? Using the locale-insensitive 
Unicode case data or for ASCII only treating non-ASCII as an error?

-- 
Henri Sivonen
hsivonen at iki.fi
http://hsivonen.iki.fi/