Seems in v.1.31->1.32 method of brute-forcing by mask was changed and thus to use the option -s (--skip=NUM) became hard task.
And seems in v.1.32->1.33 it was repaired but parameter NUM has to be 10 times less then you are going to skip. Clear and suitable.
And seems in v.1.32->1.33 it was repaired but parameter NUM has to be 10 times less then you are going to skip. Clear and suitable.