Add the following to the DTD:
<!ELEMENT crid (#PCDATA)>
<!ATTLIST type CDATA #IMPLIED>
This element represents a CRID (Content Resource Identifier), which can be used as a form of unique ID for the particular programme being broadcast -- useful for de-duplicating, spotting repeats, following series, and the like. It can also potentially be used to obtain other metadata about the programme, where such metadata is provided -- see the TV-Anytime standards, for example.
The type data should be one of "item", "series", "recommendation", or a hex code representing the CRID type (if unknown), written as (e.g.) "0x31". I'm not sure how to represent that in a DTD -- it's been a while since I played with one.