709

709 is a number that can refer to several different things in mathematics, telecommunications, and media technology. In mathematics, 709 is a prime number.

In Canadian telecommunications, area code 709 serves Newfoundland and Labrador, covering the province’s major population centers including St. John’s.

In video and imaging standards, 709 appears in two related contexts. ITU-R BT.709, commonly referred to as Rec. 709, defines the color space, gamma curve, and matrix coefficients used for high-definition television. SMPTE ST 709 is a related standard used by the film and television industry in the United States to specify HD colorimetry for mastering and distribution pipelines.

In telecommunications networking, ITU-T G.709 is the standard for the Optical Transport Network (OTN). It specifies the framing structure, multiplexing, and forward error correction used to transport high-capacity data over optical fiber.

The number 709 also appears in various numbering conventions and identifiers beyond these contexts, but the above are the most widely recognized associations.