Computed Tracker Field
You use # for indicating fieldIds and +,*,/,- and parenthesis for operations.
For example, if you have a field with an Id of 3 which has a numeric quantity, and a field with an Id of 4 which has an item price, to multiply quantity and price: #3*#4
A file containing a little script to sync a computed field is attached to this page. This is useful when you add a new computed field on existing items for instance.
Since Tiki 15.0 (or 14.2, 12.5), you can indicate: