L. means first entrance, left. R. first entrance, right. S. E. L.
second entrance, left. S. E. R. second entrance, right. U. E. L. upper
entrance, left. U. E. R. upper entrance, right. C. centre. L. C. left
centre. R. C. right centre. T. E. L. third entrance, left. T. E. R.
third entrance, right. Observing you are supposed to face the
audience.