This directive can be used as a shortcut for a new {$IF } directive inside an {$ELSE } clause:
{$IF XXX}
  // XXX Code here
{$ELSEIF YYY}
  // YYY code here
{$ELSE}
  // And default code here
{$ENDIF}
is equivalent to
{$IF XXX}
  // XXX Code here
{$ELSE }
{$IF YYY}
  // YYY code here
{$ELSE}
  // And default code here
{$ENDIF}
{$ENDIF}
The directive is followed by an expression like the ones recognized by the {$IF } directive.
The {$ELIFC } variant is allowed only in MACPAS mode.