Abbreviations and Symbols

The following abbreviations and symbols are used in this publication:

-     Represents zero.

A     Represents value less than $.05 million ($50,000); Employees less
      than 50.

D     Withheld to avoid disclosing data for individual companies.

N     Not available.

X     Not applicable.

DOD   Department of Defense.

DOE   Department of Energy.

NASA  National Aeronautics and Space Administration.

n.e.c.  Not elsewhere classified.

SIC   Standard Industrial Classification.