According to the datasheet here on page 2: https://www.snapeda.com/parts/SS-10-15SP-LE/Nidec%20Copal/datasheet/
Pins C and C1 are the same. You can either use 1 contact pin to turn ON Pin 1 or you can use both C and C1 to turn ON Pin 1.
Let me know if you have any other questions.
Answered 3 weeks, 2 days ago.