it means that the national forest service (or something like that) guarantees that the wood was harvested with sustainable methods. i.e. no clear cutting, no tricky poisons are put in the wood to make it weather proof, it wasnt taken from a forest that is endangered. i think you could easily find more about this with the help of friend google.

I've had certified wood

clever.

It means your lumber is coming from a managed forest. Gets you a point towards LEED certification.

it's more than just certified wood. in order to gain the LEED point, it must be certified by the Forest Stewardship Council which is a third party internationally recognized committee that evaluates forest management practices. also to gain the LEED point, there must be a verifyable chain of custody of the particular wood product both during manufacture and during construction.

that web link that Janosh has is a really good page. go to where it shows the comparison of the different certifications for the forests and pay attention to the 'governance' of the certification. some certification processes are "self regulated". can you really take a forests manager's word that they are "practicing sustainable techniques" since they say so themselves? FSC really holds the management of a forest accountable for their practices.