-P "0x1 2 03" - maybe better as "\x1\x2\03"
-P "file:/tmp/payload.dat" or -P "/tmp/payload.dat"
-P "random:100" (100 bytes of random data)
-P "string:GET HTTP/1.0\n\n" or -P "GET HTTP/1.0\n\n"
-P "pattern:20:abcd"
-P "pattern:1024:\x0"

Combination:

-P "file:/tmp/payload.dat:random:100:\x1\x2\03:GET / HTTP/1.0\n\n"
