That is also true --- for example, "mov reg, reg" is a special case of "mov reg, r/m" or "mov r/m, reg" with the r/m specifying a register, so basically two separate sequences of bytes which perform the same operation. This has been exploited by copy-protection and steganography, going back to the A86 shareware assembler which was the first use of this technique that I can remember, to more recent developments:
