Part numbers and phase numbers

You will see that each camshaft has a Part No and Phase No.

The Part Number designates the make and model/the duration period of the inlet camshaft/the valve lift of the inlet camshaft and whether the camshaft profile is hydraulic.
So if we look at the Ford 1300/1600 CVH RS Turbo XR3i XR2 Camshaft Data Sheet we see the following:-

FORC/206/420/H PH2

FORC – Specifies the make and engine type
260 – Specifies the duration
420 – Specifies the lift on the inlet valve
H – Specifies that the camshaft is designed for hydraulic cam followers
PH2 – Specifies the type of use the camshaft is recommended for