led yard   A yard (abbreviation: yd) is a unit of length in
several different systems, including English units, Imperial
units, and United States customary units. Its size can varies
from system to system. The most commonly used yard today is the
international yard, which is equal to 0.9144 metre.  The yard is
used as the standard unit of field-length measurement in the
American, English, and Canadian games of football (although
Canada has officially adopted the metric system).  The Traffic
Signs Regulations and General Directions 2002 only provides for
the use of yards and miles when showing distances on British
road signposts. But, in 2007 and 2008, many driver location
signs using kilometers to specify the distance from specified
reference points were erected on many British Motorways.  A
corresponding unit of area is the square yard.  In the context
of American and Canadian concrete mixers' loads, a cubic yard is
always called simply a yard. A typical marking would indicate
that a mixer had a capacity of