Refer to figures.
A runway designation marking shall be provided at the thresholds of paved runways, and to the extent practicable, of unpaved runways. A runway designation marking shall be located at a threshold as shown below as appropriate. If the runway threshold is displayed from the extremity of the runway, a sign showing the designation of the runway may be provided.

A runway designation marking shall consist of a two-digit number and on parallel runways shall be supplemented with a letter. On a single runway, dual parallel runways, and triple parallel runways the two-digit number shall be the whole number nearest one-tenth of the runway magnetic azimuth when viewed from the direction of approach.

In the case of parallel runways, each runway designation number shall be supplemented by a letter as follows, in the order shown from left to right when viewed from the direction of approach:

• Two parallel runways: "L" for left runway, "R" for right runway
• Three parallel runways: "L" for left runway, "C" for center runway, "R" for right runway