Each vendor contains a list of its devices.
Each device in the list has a 2-byte long id, stored the same way as vendor id (4 hexadecimal letters).
-<h2>Sub-systems</h2>
+<h2>Subsystems</h2>
A device can consist of more sub-systems.
Each sub-system has 4-byte long id, stored as 8 hexadecimal letters, split in the middle by a space (for example <tt>1234 abcd</tt> could be a sub-system id).
The first quad of digits is considered a vendor id (from the same list of vendors). The vendor of the sub-system can be different than vendor of the device.