in the United States thanks to improvements in engineering and corrosion prevention coupled with lowered production costs. However, premature failure due to corrosion is a concern when compared to wood. The National Association of Corrosion Engineers or NACE is developing inspection, maintenance, and prevention procedures similar to those used on wood utility poles to identify and prevent decay. Markings Pole brandings British Telecom posts are usually marked with the following information: 'BT' – to mark it as a British Telecom UK Pole (This can also be PO (Post Office) or GPO (General Post Office) depending on the age of the pole) a horizontal line marking 3 metres from the bottom of the pole the pole length, typically 8 to 10 metres, and size. 9L is a 9 metres long, light pole, other letters used are 'M' (Medium) and 'S' (Stout). the year of treatment and therefore generally the year of installation (e.g. the pole in the picture was treated in 2003) the batch and type of wood used A date of the last official inspection An alphanumeric designation e.g. DP 242 where DP is an initialism of Distribution Point If relevant, a red D plate meaning 'Dangerous' and indicating that the pole was structurally unsafe to climb or due to its proximity to other hazards The date on the pole is applied by the manufacturer and refers to the date the pole was "preserved" (treated to withstand the elements). In the United States, utility poles are marked with information concerning the manufacturer, pole height, ANSI strength class, wood species, original preservative, and year manufactured (vintage) in accordance with ANSI standard O5.1.2008. This is called branding, as it is usually burned into the surface; the resulting mark is sometimes called the "birth mark". Although the position of the brand is determined by ANSI specification, it is essentially just below "eye level" after installation. A rule of thumb for understanding a pole's brand is the manufacturer's name or logo at the top with a two-digit date beneath (sometimes preceded by a month). Below the date is a two-character wood species abbreviation and one- to three-character preservative. Some wood species may be marked "SP" for southern pine, "WC" for western cedar, or "DF" for Douglas fir. Common preservative abbreviations are "C" for creosote, "P" for pentachlorophenol, and "SK" for chromated copper arsenate (originally referred to salts type K). The next line of the