Suggested Defaults Guidelines

How's this:



DEFAULTS

Attributes
	If a default value exists for an attribute when it is missing
it will be specified in the DTD.  If there is no default value and the
attribute is not mandatory, a brief comment should be included in the
DTD as to the effect if and/or conditions under which it is omitted.
If an attribute is give a null value, it should have the natural
meaning of a null value for that attribute or, if there is no such
meaning, be treated as an error.  The textural description of the
attribute should reflect the information in the DTD and expand as
appropriate.
	Generally, an implied default of the most common value in the
immediately forseeable future should be provided to shorten
signatures.  Note that providing such a default does not lengthen any
case where the value is explicitly provided.

Elements
	If an element is not required to be present, a brief comment
should be included in the DTD as to the effect if and/or conditions
under which it is omitted.  Similarly, if an element is not specified
as EMPTY but may have no content, a brief comment should be included
in the DTD as to what that means.  The textural description of the
element should reflect the information in the DTD and expand as
appropriate.
	Generally, the absence of an element which would cause an
action implies that no action is taken and the absence of an element
that provides or overrides information implies that the information is
null or not overridden, respectively.
	No content for an element has the natural meaning for what the
content means is defined to have such a meaning when null.  If this is
the case, that meaning should be pointed out.  If no content is not a
meaningful value for the content of an element, it may be specified to
mean the value most likely to be desired for the content of that
element in the immediately forseeable future, if any.  Otherwise no
content for the element should be an error.



Thanks,
Donald
=====================================================================
 Donald E. Eastlake 3rd   +1 914-276-2668     dee3@torque.pothole.com
 65 Shindegan Hill Road, RR#1  +1 914-784-7913(work)  dee3@us.ibm.com
 Carmel, NY 10512 USA

Received on Friday, 15 October 1999 00:02:37 UTC