%spellRoutineSelfOnly()

    This function has specific usefulness within a BlobbieScript used to
    implement a spell. The function makes particular use of variables
    pre-defined for spell BlobbieScripts and is provided to mimic behaviour
    present in the MUD's C source code as provided via #defined MACROS.

    This function should only exist within the loop over the spell's
    @targets. This function will check that @target is the invoker of the
    spell. If not then it will jump execution of the script to the next
    loop iteration after informing the caster with the following: "You can
    only cast this spell on yourself."

    Example:

    protect
    {
        foreach( @targets as @target )
        {
            %spellRoutineSelfOnly( @target )

            // Spell does something if target is allowed.
        }
        endforeach
    }
    endprotect