RFC Errata
RFC 6321, "xCal: The XML Format for iCalendar", August 2011
Note: This RFC has been updated by RFC 6868, RFC 7529
Source of RFC: IETF - NON WORKING GROUPArea Assignment: app
Errata ID: 3316
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: Norman Walsh
Date Reported: 2012-08-12
Held for Document Update by: Barry Leiba
Section Appendix A says:
type-byday = element byday { xsd:integer?, type-weekday }
It should say:
???
Notes:
That's not a valid RELAX NG pattern. It's an attempt to group "string" and "data" patterns.