The type of usage is used to differentiate macros in the macro navigator, and specifies which of the functionalities "Generate macros automatically" and "Update macros" can be executed and which not.

0 = Not specified: Generation and updating are possible.

1 = Defining: Is only taken into consideration for generating.

2 = Referencing: Is only taken into consideration for updating.

3 = Subordinate: Neither generating nor updating is possible.

Reference

MacroBoxPropertyList Class
MacroBoxPropertyList Members