FAQ - Architecting
In FB, you've got the option to select "This file is: New - Changed - Unchanged". What do these settings mean?
Whenever you create a new fuse it's set to "new". The first time you generate a framework, any fuse that is written is now set to 'unchanged'. This happens so that subsequent exports don't automatically overwrite the fuses that you've already published and on which you've potentially started your final run of coding. By setting them to 'unchanged', the export form knows which fuses to leave unchecked for generation.
If you make a change to the fuse, you can set it to 'changed' that it included in the auto-selection for the export form. Once the framework is re-exported, any fuses that were written are once again set to 'unchanged'.