EXPLANATION OF THE STAGE DIRECTIONS.
Reading edition
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.