Ducati MULTISTRADA 1200S ABS 2015 Workshop Manual page 1048

Overhauling the piston
Clean the piston crown and piston ring grooves, removing any carbon deposits.
Visually inspect the piston and check its dimensions carefully: there must be no signs of scuffing, scoring, cracks,
or other damage.
The piston diameter must be measured at 7.5 mm up from the bottom of the skirt and in perpendicular direction
to the gudgeon pin axis.
The pistons must always be replaced as a pair.
Checking the piston-cylinder clearance
The pistons are marked with a letter (punched into the piston crown) that indicates the size class to which they
belong.
Always match piston with cylinder from the same size class.
For the correct values refer to chapter "Cylinder/piston".