CLLI code (sometimes referred to as CLLI name or COMMON LANGUAGE Location Identifier Code, and often pronounced as silly) is a Common Language Information Services identifier used within the North American telecommunications industry to specify the location and function of telecommunications equipment or of a relevant location such as an international border or a supporting equipment location, like a manhole or pole. Originally, they were used by Bell Telephone companies, but since all other telecommunications carriers needed to interconnect with the dominant Bell companies, CLLI code adoption eventually became universal. CLLI codes are now maintained and issued by iconectiv, which claims trademarks on the names "Common Language" and "CLLI". CLLI codes are useful to telecommunications companies for ordering phone service, for the rating of call detail records for billing purposes, and to assist in tracing calls. CLLI codes are associated with Vertical and Horizontal coordinates (frequently abbreviated to "V and H coordinates"), which were developed by AT&T researcher Jay K. Donald to provide a relatively simple method of calculating distance between two network locations. Various mileage-sensitive services are priced according to the V and H coordinates associated with the two endpoints' CLLI codes. Structure The first six characters of a CLLI code represent the place the code refers to and contain two code elements: Four characters to denote the geographical area and the geographical area type (for example, city, town, and borough), known as the Geographical code element. Two characters to denote the state, province, or country, known as the Geopolitical code element. The codes HS (high seas) and EO (earth orbit) are reserved for ships at sea and satellites, respectively. For the various code formats, the remaining two or five characters contain one of: A two-character building identifier, either two letters or two numbers, for telephone company buildings. Incumbent independent telephone companies will use two-letter identifiers with X as the first letter. The two-character building identifier may be followed by three characters to identify an individual switching or non-switching entity within the building. A non-building location, identified by a letter followed by four digits. A client site is identified by a digit, a letter, then three more digits for non-building locations. There are four CLLI code formats. Network Site Code Format A Network Site code represents any existing or proposed building, structure, or enclosure, where there is a need to uniquely identify one or more network functions. Network Site