APPENDIX K ITF RULES OF TENNIS Insert pegs at A and B and attach to them the respective ends of two measuring  tapes. On one, which will measure the diagonal of the half-court, take a length 53’1”  (16.18 m) and on the other (to measure the sideline) a length of 39’0” (11.89 m).  Pull both taut so that at these distances they meet at a point C, which is one corner  of the court. Reverse the measurements to find the other corner D. As a check on  this operation it is advisable at this stage to verify the length of the line CD which,  being the baseline, should be found to be 36’0” (10.97 m); and at the same time its  centre J can be marked, and also the ends of the inner sidelines (c, d), 4’6” (1.37 m)  from C and D. The centreline and serviceline are now marked by means of the points F, H, G, which  are measured 21’0” (6.40 m) from the net down the lines bc, XJ, ad, respectively. Identical procedure the other side of the net completes the court. If a singles court only is required, no lines are necessary outside the points a, b,  c, d, but the court can be measured out as above. Alternatively, the corners of  the baseline (c, d) can be found if preferred by pegging the two tapes at a and b  instead of at A and B, and by then using lengths of 47’5” (14.46 m) and 39’0” (11.89  m). The net posts will be at n, n, and a 33’0” (10 m) singles net should be used. When a combined doubles and singles court with a doubles net is used for singles,  the net must be supported at the points n, n, to a height of 3 feet 6 inches (1.07  m) by means of two singles sticks, which shall be not more than 3 inches (7.5 cm)  square or 3 inches (7.5 cm) in diameter. The centres of the singles sticks shall be 3  feet (.914 m) outside the singles court on each side. To assist in the placing of these singles sticks it is desirable that the points n, n,  should each be shown with a white dot when the court is marked. When sanctioning bodies approve so called “Blended Lines” on courts the  following guidelines must be followed: Colour: • Within the same colour family as the background playing surface. • Lighter than the background playing surface. • Limit on colour variation of +22 points on the L* scale (Add 25% by volume of white paint to the background colour) 474