Bingo! I've had the same thought as I've grappled with those who only affirm the Five Points of Calvinism and attach the adjective 'reformed' to themselves. I've blogged about this before (see tab entitled 'reformed theology') and don't need to repeat that information. If you are new to this discussion you would do well to see the link to Richard Muller's fine article, "How Many Points?"
Darryl Hart has chimed in with a thoughtful piece Why Not Lutheran Baptist? to answer this question. He reviews the recent skirmish between James White and R. Scott Clark over the use of the adjective, 'reformed.' Clark takes a pretty traditional view on the use of that term. White caricatures that position.
Yesterday I came across another post at the Confessional Outhouse on the same topic. Steve Zrimec does a good job illustrating the difference between those who affirm a particular confession (i.e. many reformed Baptists) and those who subscribe to a confession (i.e. confessional Reformed folk). A Confessionalist By Any Other Name. To affirm a creed or confession falls short of binding oneself to it and the propositional truths contained therein. To subscribe to a creed or confession is to sign one's name on the dotted line and profess before the church that this document is a faithful summary of Scripture. Furthermore, one is binding himself to teach within the bounds of such a document. So the difference between a Reformed Baptist pastor who follows Spurgeon and a minister in a reformed denomination is a lot larger than one might think.
I'm not casting stones at my reformed Baptist friends nor am I suggesting that they find a new title. I love them dearly and enjoy their company. What I am suggesting is that we think carefully about how we apply the term 'reformed.'