The repeated letters are to say "not necessarily the collector of _this_ transistor (which may be, for instance, the bottom of a push-pull pair), but the collec

The repeated letters are to say "not necessarily the collector of _this_ transistor (which may be, for instance, the bottom of a push-pull pair), but the collector of the most-collector-ward transistor". Explained here: https://en.wikipedia.org/wiki/IC_power-supply_pin https://en.wikipedia.org/wiki/IC_power-supply_pin