Here is an image showing the pin diagram of this transistor.
Classification of hFE
The KSC1623-G transistor can have a current gain of 200 to 400. The gain of the KSC1623 will be in the range from 90 to 600, for the KSC1623-L it will be in the range from 300 to 600, for the KSC1623-O it will be in the range from 90 to 180, for the KSC1623-Y it will be in the range from 135 to 270.
Marking
The KSC1623-G transistor is marked as "C1G".
Complementary PNP transistor
The complementary PNP transistor to the KSC1623-G is the KSA812-G.
Replacement and Equivalent for KSC1623-G transistor