Trigger links allow you to do things like sending your contacts a link customized with their information or set "triggers" to fire when someone clicks a link.
Here's how to create them and use them.
To convert a calendar link to one that auto fills the contact details, append the link with this:
If you're using the standard calendar (with no custom form) use this:
If you've customised the calendar form to use a custom form (with full name) use this: