| | 12 | * For every format and its extensions, the registry: |
| | 13 | * should be able to list the supported things. |
| | 14 | * if user tries to save current book in a particular format: |
| | 15 | * the registry should check what of the things will actually be saved. |
| | 16 | * if some things are not to be saved - the registry should provide that these are not supported by the format. |
| | 17 | * if the client provides a new extension of a particular format: |
| | 18 | * the things that are about to enter the format and be persisted, should be registered in the registry as well so that it respond correctly to saving in and loading from that particular format. |
