Branch over following JMP ($nnnn) instruction
A branch with argument $03 skips the following 3 bytes.
A JSR instruction has the initial byte value of $20.
Therefore $F0 $XX $20 is part of a 
Bxx +
JMP ($xxxx)
*

instruction sequence.
This is a very common construction, and the logical way to 
conditionally call a routine via a vector, and therefore is not copyrightable.