You make bibliographical references using square brackets:
...as described in [RFC2739].
In the end of the document you create the bibliography section with references tag:
<<references: Reference section title
[RFC2739] T. Small, D. Hennessy, F. Dawson: "Calendar Attributes
for vCard and LDAP", RFC2739, IETF, 2000.
[vCard21] Internet Mail Consortium, "vCard - The Electronic
Business Card Version 2.1",
http://www.imc.org/pdi/vcard-21.txt, September 18, 1996.
>>
In the references section you describe the references. You start a reference by the bracketed tag that was used in the text to refer to it and follow that by description of the reference. No special structure exists for the description.
If you want to use structured database to keep and format your descriptions, you can write a perl(1) program to generate the references in the format you like from the database and use the PlainDoc inclusion facilities to bring them into your document.
It is possible to have more than one bibliography, simply use different title for them, e.g. "Normative" vs. "Informative". If you do not supply any title, the default title of the underlying formatting system is used.