RE: John's proposed wording for Principle 4

<proposed>
Principle 1. Content must be able to work with current and future
technologies
</proposed>

Concerning the 4 Principals overall, how is the keyword *must* being
interpreted? Is it understood to mean the same as *MUST* in accordance with
RFC 2119 [RFC2119] <http://www.w3.org/TR/xhtml-media-types/>  or is it
definitely a *must* as sometimes interpreted as an RFC2119 *MAY*?

If it is really a *MUST* then it should be capitalised and there needs to be
a reference somewhere within the documents back to RFC2119.

If it is really a *must* then it becomes ambiguous. In this case however, I
propose that all 4 Principals (taking into account Johns proposal) could be
written thus:

1. Content is perceivable
2. User interface components in the content are operable
3. Content and controls are understandable
4. Content is able to work with current and future technologies

Regards,

Neil Whiteley