John Caron writes:
# I am still unclear: if the internal DTD declares an element, what happens if
# the external DTD does also?
The validator will complain that the element was declared more than once.
# If the second declaration gets ignored
Not ignored--carefully scrutinized and upbraided for its impertinence.
# Are you referring to this line in the Capabilities DTD? It seems very
# similar to what Joe was trying to do. Were you trying to make a standard
# list that could be extended?
The XML you cite is from the older WMS version 1.0--see
<http://www.digitalearth.gov/wmt/xml/> for DTD and sample XML.
# <!-- This WMT-wide list of possible output formats can be redefined by
# individual servers; see the sample XML. -->
# <!ENTITY % KnownFormats " GIF | JPEG | PNG | WebCGM | SVG | GML.1 | GML.2 |
# GML.3 | WBMP | WMS_XML | MIME | INIMAGE | TIFF | GeoTIFF | PPM | BLANK " >
Seeing this reminds me that you *can* redefine an ENTITY (but not an
ELEMENT) using the internal DTD. This may suit your needs. WMS 1.1.x
no longer uses this mechanism (because element names like <GIF/> were
replaced by MIME type text values like <Format>image/gif</Format>).
-Jeff DLB
