Do halflings get +1 THAC0 *and* +1 damage with a sling?

I just read somewhere (here: http://www.pocketplane.net/volothamp/chap4c.htm) there that halflings get +1 THAC0 *and* +1 Damage bonuses when using slings, but I thought it was just +1 THAC0 like elves with bows and swords, could someone confirm which is correct? Thanks