Drop normative references to OPAQUE and Privacy Pass (cfrg#369)

draft-irtf-cfrg-voprf.md

@@ -135,9 +135,9 @@ equivalent to a VOPRF.
 
 OPRFs have a variety of applications, including: password-protected secret
 sharing schemes {{JKKX16}}, privacy-preserving password stores {{SJKS17}}, and
-password-authenticated key exchange or PAKE {{!I-D.irtf-cfrg-opaque}}.
+password-authenticated key exchange or PAKE {{?OPAQUE=I-D.irtf-cfrg-opaque}}.
 Verifiable OPRFs are necessary in some applications such as Privacy Pass
-{{!I-D.ietf-privacypass-protocol}}. Verifiable OPRFs have also been used for
+{{?PRIVACYPASS=I-D.ietf-privacypass-protocol}}. Verifiable OPRFs have also been used for
 password-protected secret sharing schemes such as that of {{JKK14}}.
 
 This document specifies OPRF, VOPRF, and POPRF protocols built upon