For some reason I can never remember the syntax to refer to an Internet Draft in a draft. I wrote up a note somewhere, but I've managed to lose it!
First, add the include: ?rfc include='reference.I-D.ietf-dnsop-sutld-ps-04.xml' This includes "draft-", the version and .xml
NOTE: Leave draft- off when referencing a generic draft name, and add draft- when referencing a specific version of an internet-draft.
Next, add the refernce: target="I-D.ietf-dnsop-sutld-ps" This does not have the "draft-", the version and .xml. The refernce anchor can also be found by looking in the refernce itself (e.g: https://xml2rfc.tools.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-dnsop-sutld-ps.xml)
More information here: https://xml2rfc.tools.ietf.org/.