The check digit is used to confirm the initial digits of the card number. The benefits of using a checksum is that it prevents casual attempts to invent credit card numbers, as only one in ten will be valid.
Length (adj). the longest, or longer, dimension of any object, in distinction from breadth or width; extent of anything from end to end; the longest line which can be drawn through a body, parallel to its sides; as, the length of a church, or of a ship; the length of a rope or line.
From Wikipedia, the free encyclopedia. A cable length or cable's length is a nautical unit of measure equal to one tenth of a nautical mile or approximately 100 fathoms. The unit is named after the length of a ship's anchor cable in the age of sail.The definition varies: 1  International: 1â10 nautical mile, or 185.2 m.2  Imperial (Admiralty): 1â10 Admiralty mile, or 608 ft (185.32 m), about 101 fathoms.he unit is named after the length of a ship's anchor cable in the age of sail. The definition varies: 1  International: 1â10 nautical mile, or 185.2 m. 2  Imperial (Admiralty): 1â10 Admiralty mile, or 608 ft (185.32 m), about 101 fathoms.