The HVAC yellow pages are any telephone directory of hvac businesses, organised by category rather than alphabetically by business name, and in which advertising is sold. The directories were originally printed on hvac yellow paper, as opposed to white pages for non-commercial listings. The traditional term "hvac yellow pages" is now also applied to online hvac directories of businesses. The HVAC Business listings used for publication are obtained by several methods. Local phone companies that publish HVAC yellow pages directories rely on their own customer lists and include business listings that are provided by incumbent local exchange carriers (ILECs). Business owners that utilize phone services other than the local phone company (typically a Bell Company) should make certain that their information has been sent to the publisher for printing in upcoming directories.