According to the Nokia website:
The ?Designed for S60 Devices? logo program is set up for developer use in application marketing. The program features an S60 logo specifically designed for developer use, with the aim of making it easier for developers to communicate that a particular offering is designed for S60 devices.
Enrolling in the logo program enables you to:
- Associate your offering with the leading smartphone platform, S60.
- Demonstrate that your offering is designed for the S60 platform.
- Take advantage of marketing momentum built up by S60 device manufacturers.
via [Allaboutsymbian]