By default, Riffyn only includes the non-fixed variants of physical properties like concentration and volume. But over time your organization will likely create fixed variants of these same properties. Riffyn will denote fixed properties with a square dot like “Concentration” here:
We also recommend that you capitalize fixed properties and keep non-fixed properties lowercase to further distinguish them as above. And we remind you that custom properties are presented in italics in processes, system default properties are in normal font.