Given that the maximum supported note size is 1024 bytes, the provided buffer area (if any) must be at least as big as 1024 bytes when reading or deleting a note. Since the application has no ability to specify the maximum size note that the note pad needs to support, XCF assumes that all note pads support 1024 byte notes. As a consequence, should it be the case that the application only uses null notes, it must still provide a 1024 byte buffer when reading what is always known to be a note with no content.

Given that only two note sizes are supported (0 and 1024), the buffer length must be either 0 or 1024 when creating, writing, or replacing a note.