Architectural and philosophical points
These statements of architectural principle explain the thinking behind the specifications. These are personal notes by Tim Berners-Lee: they are not endorsed by W3C. They are aimed at the technical community, to explain reasons, provide a framework to provide consistency for for future developments, and avoid repetition of discussions once resolved.
Simplicity
Modular Design
Being part of a Modular Design
Tolerance
Decentralization
Test of Independent Invention
Principle of Least Power
Why doesn't HTML include tags for style? Why can't you put text inside SMIL? Why doesn't CSS include commands to transform a document? Why, in short, does W3C modularize its specification and why in this particular way? This essay tries to make explicit what the developers in the various W3C working groups mean when they invoke words like efficiency, maintainability, accessibility, extensibility, learnability, simplicity, longevity, and other long words ending in -y.