The exrules parameter takes a semicolon-separated list of quoted recurrence rule strings where each rule is an excluded recurrence of the event.
For example, the following exrules parameter specifies a recurring event that does not recur at the times specified by the two rules:
The first rule is for the event not to occur daily for 10 instances. The second rule is for the event not to occur weekly for 4 instances (COUNT=10;FREQ=DAILY and FREQ=WEEEKLY;COUNT=4).
The following example URL passes the example exrules parameter:
http://webcalendarserver/storecomponents.wcap ?id=b5q2o8ve2rk02nv9t6 &calid=jdoe &uid=333 &dtstart=20020301T112233Z &exrules="count%3D10%3Bfreq%3Ddaily"; "freq%3Dweekly%3Bcount%3D4" &rrules="count%3D100%3Bfreq%3Ddaily" &dtend=20020301T112233 &summary=uuuu