31. 803 is one of the original 86 North American Numbering Plan area codes assigned in 1947. 32. DDD was the term used when the North American Numbering Plan was implemented in the 1950s. 33. Under the original North American Numbering Plan of 1947, area code 503 covered all of Oregon. 34. In addition, the PRC numbering plan reserves space for Taiwan, but they are not currently used. 35. All 110 examples went into the numbering plan . 36. Though it was part of the original 1926 numbering plan , it was deleted within 10 years. 37. These systems use a closed telephone numbering plan . 38. Under the original North American Numbering Plan of 1947, area code 402 covered all of Nebraska. 39. The North American Numbering Plan decided that northwest Pennsylvania would receive the new code of 582. 40. For the telephone numbering plan context of 070 numbers see Telephone numbers in the United Kingdom.
