Parameters:

  * F   This flag provides UNIX to host name file mapping on non-UNIX machines.
 
  * L   Left justify and remove leading blanks from value. If n is nonzero it defines the width of the field,
     otherwise it is determined by the width of the value of first assignment. When the parameter receives
     a value, it is filled on the right with blanks or truncated to fit into the field. Leading zeros are removed if 
     the -Z flag is also set. This turns the -R flag off.
 
  * R   Right justify and fill with leading blanks. If n is nonzero it defines the width of the field, otherwise
     it is determined by the width of the value of first assignment. The field is left filled with blanks or truncated
     from the end if the parameter is reassigned. This turns the L flag off.
 
  * Z   Right justify and fill with leading zeros if the first nonblank character is a digit and the -L flag has not been
     set. If n is nonzero it defines the width of the field, otherwise it is determined by the width of
     the value of first assignment.
 
  * e   Tag the parameter as having an error. This tag is currently unused by the shell and can be set 
     or cleared by the user.
 
  * f   The names refer to function names rather than parameter names. No assignments can be made
     and the only other valid flag is -x.
 
  * i   The name is an integer. This makes arithmetic faster. If n is nonzero it defines the output arithmetic
     base, otherwise the first assignment determines the output base.
 
  * l   All uppercase characters converted to lowercase. The uppercase flag, -u is turned off.
 
  * p   The output of this command, if any, is written onto the two-way pipe.
 
  * r   The given names are marked read-only and these names cannot be changed by subsequent
     assignment.
 
  * t   Tags the name. Tags are user definable and have no special meaning to the shell.
 
  * u   All lowercase characters are converted to uppercase characters. This turns the
     lowercase flag, -l, off.
 
  * x   The given names are marked for automatic export to the environment of subsequently
     executed commands.