Miele Built-in coffee machine Operating And Installation Instructions page 17

The following applies to appliances with stainless steel
surfaces:
~
Do not adhere stickers, adhesive tape or any other adhesive
materials to stainless steel surfaces. The coating on the stainless
steel surfaces will become damaged and lose its protective
properties against soiling.
~
Stainless steel scratches very easily and even magnets can
cause damage to the surface.
Warning and Safety instructions
17