You may want to read part 1 if you haven't already. I have explained why we might want to have synchronisation. Now I'll explain how we would do that.

First we need to understand how PIM data are or can be formatted. Actually there are various formats, more or less proprietary. And there are a couple of IETF format, vCard, vCalendar and iCalendar. iCalendar is the version 2.0 of vCalendar, and has been ratified as RFC 2445 by the IETF. It is the standard for storing calendaring information. vCard has been ratified as RFC 2426 and specifies a way to store and transmit contact information.

Both iCalendar and vCard have a common organisation, that is logical given the nature of the data. We have records that contain fields, with attributes. For example, a contact would be as follow:

FN:Homer Simpson
ORG:Springfield Nuclear Plant
ADR;TYPE=HOME:;;742 Evergreen Terrace

The vCard is a record, and each field is one of this lines that starts with a keyword followed by a ":", at least when it comes to the vCard format. iCalendar is quite similar, but allow embedding another record. No big deal. This is the logical organisation, and if you look closer, you'll realize that this is the design choice made for the Palm .pdb format where the data is just a bunch of records.

To be continued...