IMSC1 Comments - More #1

   - It doesn't make sense to stipulate that the initial value of color
   shall be white in a context defining document usage. This is an
   implementation requirement (only).
   - Similarly, it doesn't make sense to specify that font family of
   default means monospaceSerif as a document requirement; it is an
   implementation requirement. Also, this is probably inappropriate depending
   on the language market; e.g., in the Japanese market, it should be
   monospaceSansSerif or proportionalSansSerif.