Ducati Diavel Workshop Manual page 691

Cylinder head assemblies: camshafts
Apply in the four areas of the cylinder heads surface a strip of about 2 mm (MAX. about 4 mm) of sealant (liquid sealant
Three Bond 1215), observing the heights and position indicated in figure.
Cylinder head cover identification: The vertical head rocker cover (6) has a nib (A) on the left-hand side (exhaust side),
whereas rocker cover (5) has a nib (B) on the right-hand side (exhaust side).
Locate the cover (6) on the cylinder head, aligning the four fixing holes.
Start the screws (7) with the O-rings (8).
Tighten the screws (7) to a torque of 10 Nm (Min. 9 Nm - Max. 11 Nm) (Sect. 3 - 3, Engine torque settings) following the
sequence above.