I use it on here to mean some variant of a minarchist - and when I talk about anarcho-capitalism I usually refer to it by that name ("anarcho-capitalism") or a similar one.
That definition in and of itself can mean a lot of things, of course, but this definition on the Bleeding Hearts Libertarian blog is next to useless. Fernando Teson writes:
"By “libertarian institutions” I mean here institutions that allow all kinds of mutually beneficial arrangements, which include exchanges in private markets and government-induced correction of market failures, along with constitutional constraints on the power of government to avoid government failure."
OK, but this is what almost every American that talks or writes about government and the economy supports. What is this supposed to demarcate, really? Not only do I support libertarian institutions under this definition, but I am an extremely partisan libertarian (if this is what a libertarian institution is).
I get the same sense from Mark Pennington and just about everything I've ever read about "robust political economy". It's a defense of a constitutionally limited, federal government in a market society. We all support that. To be sure, Pennington et al. do a superb job putting into words the reasons why we all support that. But we all do. It's not productive to call this libertarianism.
UPDATE: And a word of advice to commenters. If your instinct is to inform me that I don't actually think something that I am under the impression that I do think - stop. Stop writing. Just save us all the trouble.