Set managed properties for columns
Managed properties only apply when you include columns in a managed solution and import the solution into another environment. These settings allow a solution maker to have some control over the level of customization that people who install their managed solution can have when they customize this column. To set managed properties for a column, select Managed Properties on the menu bar.
The Can be customized option controls all the other options. If this option is False, none of the other settings apply. When it is True, you can specify the other customization options.
If the column is customizable, you set the following options to True or False.
Display name can be modified
Can change requirement level
Can change Additional Properties
These options are self-explanatory. If you set all the individual options to False, you might as well set Can be customized to False.