|Handbook 159GlossaryAutomatic reduction. Many fax machines will automaticallyreduce documents being transmitted to accommodate theeffective printing width of the receiving unit. This allows, forexample, a fax machine with a 10" scanning width to send animage 10" wide to a unit with an 8.5" print width; thereceiving fax machine will receive a reduced-size printout ofthe complete image.Bits per second. See bps.Black density. Also called black coverage. The amount ofnonwhite area on a page. For example, most regular officecorrespondence has a black density well under 10%, due tothe presence of margins, spaces between words, spacesbetween lines and paragraphs and even spaces within letters(such as e and o). However, drawings and photographs have amuch higher black density, sometimes approaching 100%.The higher a page’s black density, the more slowly a faxmachine can send it.This glossary contains terms and words you may encounterwhen discussing or reading about fax machines and faxcommunications. Please use these definitions for referenceonly.A4, B4, A3. Standard stationery sizes defined by theInternational Standards Organization, an agency of the UnitedNations. A4 = 211 x 297 mm; B4 = 257 x 432 mm; A3 = 297x 419 mm.Auto Dial. Enables user to store preprogrammed telephonenumbers in the unit’s memory. Storage capability varies fromunit to unit.Automatic fallback. The ability of a fax machine, whencommunicating with another fax which is communicating at aslower rate, to slow down (“fall back”) to the other unit’sspeed.
