The FREE statement empties selected keeplists or removes a database key
  value from a keeplist or currency indicator.

  Format -

        {         [        { record-name } ]          }
        { CURRENT [ WITHIN { set-name    } ]          }
        {         [        { realm-name  } ]          }
   FREE { { OFFSET integer-exp }                      }
        { { FIRST              } WITHIN keeplist-name }
        { { LAST               }                      }
        { ALL [ { FROM { keeplist-name } ... } ]      }
        {     [ { CURRENT                    } ]      }

        [ ON ERROR stment ] [ NOT ON ERROR stment ]

        [ END-FREE ]

1 - record-name

  is a subschema record name.

2 - set-name

  is a subschema set name.

3 - realm-name

  is a subschema realm name.

4 - integer-exp

  is an arithmetic expression or integer.  It refers to a position in
  keeplist-name.  Integer-exp cannot be zero.

5 - keeplist-name

  names a keeplist in the Sub-Schema Section.

6 - stment

  is an imperative statement.