Historically there has only been one lock slot shape, so all the computer locks available on the market were compatible with all the computers.
In response to thinner hardware, there are now three lock formats on the market, and the lock jaws are not cross-compatible.
The 3 formats are difficult to tell apart, and some manufacturers (HP) now use all 3 lock formats across their NPD, leading to confusion in the market, especially in Enterprise customers with mixed hardware

Targus’ universal 3-in-1 locking solution makes life simple: Each lock ships with 3 interchangeable lock heads. Simply select the compatible head for your device’s locking slot. The world's first universal locking solution. From Targus.