The .VCS format is used by a bunch of calendaring tools like outlook, iCal and Ximian Evolution.
All of them freak out over unexpected .vcs input. Here's an example vcs entry:
BEGIN:VCALENDAR VERSION:1.0 BEGIN:VEVENT ORGANIZER;CN="Bob Johnson":MAILTO:bob@blah DTSTART:20041112T190000 DTEND:20041112T230000 SUMMARY:Some event DESCRIPTION:This is an event END:VEVENT END:VCALENDARProblems I have encountered:
BEGIN:vCalendar
DTEND:20041112T250000