This article explains how to create a single Property who's value is different depending on which release flags are chosen at build time. For example if a project has 2 different releases which each use a different release flag:
Example: Release 1 flags _FLAG1_
Release 2 flags _FLAG2_
Value to be set (by _FLAG1_) MYPROPERTY = "Value1" Value to be set (by _FLAG2_) MYPROPERTY = "Value2"
This can be achieved by creating 2 "New Set Property" custom actions which create the same Property but have different conditions: