DTDs do not support this. This is supported by XML Schemas.
Michael Lillis wrote:
> Is there any XML attribute type which I can place in the following syntax
> for a DTD
> Syntax: <!ATTLIST element_name attribute_name attribute_type default_value>
> DTD example: <!ELEMENT message_seq_no #PCDATA>
> <!ATTLIST message_seq_no number 'xxxx' "0">
> which will only message sequence numbers which are greater than zero?
> i.e. the xml line looks like