Delta-like descriptions for Thiele 0.3 draft

Robert A. (Bob) Morris ram at CS.UMB.EDU
Tue Nov 7 08:42:57 CET 2000

Kevin Thiele writes:
 > Date:         Tue, 7 Nov 2000 22:14:33 +1100
 > Bob Morris wrote:
 > | II. Global feature values (This may be a Delta question).
 > |
 > | In 0.3's Examples 8 and 9 there do not seem to be any global feature
 > | values. Instead, all possible values are completely local to
 > | features. For example, can there be a list of feature values
 > | containing both "present" and "absent" to which any feature can refer,
 > | whether or not those values are in that feature's local list of
 > | values? Or rather, must every feature that wishes to allow those
 > | values name them in its list of possible values>
Kevin replied

 > I think all values should be specifically named. It would be silly to have a
 > global "present", then have a feature "Flower colour" that allows this
 > feature value.

Bob writes:

Having global named values doesn't imply that an application *must*
use them, only that it *may* use them. Also, this is one of those
places where having a schema (= DTD or X Schema) can help because it
is possible to define the schema in such a way that 'Flower colour
present' would be prohibited. In this case a validating XML parser
would signal exactly where the "error" lies, in case you care. But
even better, an application that was built to the schema but did not
enforce the schema would just ignore the silly statement.

More information about the tdwg-content mailing list