Adding a related sales order to the calendar event

[joebordes]

tabid is a unique number that each module is given in the system. each module when it is installed is given one, the base modules usually have the same one because they are installed in the same order during install but that is not mandatory.
You can see the list of assigned tabids in vtiger_tab table
this number is used freely through out the application to identify a module.

I don't know what the type is, may be "Event" and "Task" which are in the same table but logically separated in the code ??

HTH