Don't change field names in SeedCode_Subscribe_Setup.fmp12
When you subscribe to a calendar using the "Private Link" URL, certain fields in SeedCode_Subscribe_Setup.fmp12 are referenced by name. These field references are hard-coded in the .phar file. For that reason, don't change their names! These are the fields that appear on the "CalendarsXML" layout. Also, don't remove any of the field objects, or the "Filters" portal, from that layout.
Prohibited characters in field names
None of the fields you use from your FileMaker file may contain a period (.) or quotation mark (") in its name.
In iCal on your Mac, only the URLs that start with "http://" in the field you map to the "URL" field in SeedCode_Subscribe_Setup.fmp12 will appear as clickable links that open in your default browser. URLs in any other fields (e.g., the "Description" field) will not be clickable in iCal.
In iOS, URLs in any field will open in Safari, and addresses will open in Maps. And if you click on a phone number in any field, your iPhone will offer to call that number.
See ClickableLinks for more tips.