Where I can find definition of unknown Apple tag generated by Exiftool using "-u":
[Apple] 0x000d Apple_0x000d
[Apple] 0x000e Apple_0x000e
[Apple] 0x0010 Apple_0x0010
[Apple] 0x001f Apple_0x001f
[Apple] 0x002b Apple_0x002b
[Apple] 0x002d Apple_0x002d
[Apple] 0x002e Apple_0x002e
[Apple] 0x0036 Apple_0x0036
[Apple] 0x0037 Apple_0x0037
[Apple] 0x003b Apple_0x003b
[Apple] 0x003c Apple_0x003c
[Apple] 0x004a Apple_0x004a
Apple doesn't release any specs for MakerNotes like this. Almost all camera manufacturers do not release any specs for their Makernotes. It's all discovered by people doing a lot of testing to try and figure these things out.