CLC / RTS / JSR $xxxx

CLC / RTS the obvious and simplest way to clear the carry flag
when returing from a routine.  Many of the routines in the C64 KERNAL
public API indicate that they use the carry flag to indicate success
or failure, hence how often it shows up in the C64 KERNAL itself.
That a JSR instruction happens to be the first instruction in whatever
follows actually highly likely through chance, since several percent
of all instructions in a typical 6502 program are JSR instructions.

Not copyrightable.