Remarks 

The $ELSEIF directive allows multi-part conditional blocks where at most one of the conditional blocks will be taken. $ELSEIF is a combination of a $ELSE and a $IF.  

For example:

{$IFDEF  foobar} 
       do_foobar 
    {$ELSEIF  RTLVersion >= 14} 
        blah 
    {$ELSEIF  somestring = 'yes'} 
        beep 
    {$ELSE} 
        last chance 
    {$IFEND} 
    

Of these four cases, only one will be taken. If none of the first three conditions is true, then the $ELSE clause will be taken. $ELSEIF must be terminated by $IFEND. $ELSEIF cannot appear after $ELSE. Conditions are evaluated top to bottom like a normal "if ... else if ... else " sequence. In the example above, if foobar is not defined, RTLVersion is 15, and somestring = 'yes', only the "blah" block will be taken not the "beep" block, even though the conditions for both are true.