Burnishing is the process that occurs as the pads and disc wear into one another. ¹⁾
Burnishing is complete when the pad and disc contact surfaces are fully worn into each other, thus providing maximum contact.
Early disc brake systems with organic type pad materials needed fairly harsh break-in braking to burnish the disc and pads.

Note: Using 1991 and earlier brake pads with 1992 stainless steel rotors will cause premature rotor wear. ²⁾
For maximum service life, a new brake rotor should only be installed with the recommended replacement brake pads.
If you install a new rotor, also install the recommended brake pads for that particular rotor.

1992 Brake Pads and Stainless Steel Brake Discs.
With the change in brake disc and pad material for 1992, comes a change in the break in burnishing procedure.
The new combination of a softer disc and more aggressive sintered metal pads allows the normal burnishing process to scratch the disc more than before.
This grooving is normal and will diminish after burnishing is achieved.
With the new combination, burnishing can no longer be achieved by making repeated hard stops.
In fact, this practice can cause premature wear.
Repeated hard stops can generate excessive heat causing material transfer between pads and disc.
Burnishing pads and discs can only be done properly by normal brake operation through the vehicle's break-in period.