Disable a field for input, without deleting it (to not lose old data) I have a field in my customer profile (shipping/billing, doesn't matter which).
I don't need this field anymore on checkout, but I want to keep the data of older orders.
(this can be extended to any entity type, it just happens that commerce customer profile is my use case)

Is it possible to somehow disable the field for input, but not really delete it?

Ideally with a UI solution.
I already know hook_form_alter() would do the trick..
You can use the Field Permissions module to remove permissions for users to access the field.