Unnecessary extra Principle 4

Name: Mario Batusic
Email: mario.batusic@jku.at
Affiliation: Johannes Kepler Universität Linz, Austria
Document: W2
Item Number: Guideline 4.1: Maximize compatibility with current and future user agents...
Part of Item: 
Comment Type: general comment
Summary of Issue: Unnecessary extra Principle 4
Comment (Including rationale for any proposed change):
The concept of \"robustness\" is not intuitive understandable and will be a difficulty for the most content-only authors. Also talking about parsing in 4.1.1 etc. could be an additional problem for content-only authors (non-technicians).

Proposed Change:
Move shortened versions of 4.1.1 and 4.1.2 somewhere under the Principle 1, because a content that is not valid (according to an recommended standard DTD) or not well-formed will possibly break a User Client and/or Assistive Technology Software.