Before commercial release it is necessary to obtain a card ID. If two commercially released cards shared an ID, then inserting both into the machine could cause serious problems for the card manager, and it is most important that this should not happen. The bits explicitly given above will be true for all external IDs - alternative settings of these bits are reserved for future internal applications.
Next, the card manager expects to find the application front DOR starting in the top bank of the slot, at bank offset $3FC0. This section should be identical for all application cards, apart from the address of the first application DOR. The 3 byte links consist of a 2 byte offset within a bank (low byte, high byte) followed by a bank number.
It is recommended but not necessary that all the application header information, including menus and help, are placed in the top one or two banks. The space between the application front DOR and the card header above it should be padded with zeros.
Note: The bank numbers should be offset from the top bank. ie. the top bank should be $3F, the one below $3E etc. In a 128K EPROM the lowest bank should be thought of as $38 and not as $00.