@boomerang,
In a few words, there's no universal standard.
{Warning: as a prof photog, I avoid and advise my friends to avoid Refurb units. The trouble and worry are not worth the meager savings before and after the short warranty period is up.}
However, can you be specific about in which venue? For example a major used camera publication Shutterbug has certain standard for used equipment mint, near mint, etc. Some classified ad publications use other various standards, But none indicate the relative wear of refurb.
So the label 'Used' has a different connotation ...and may be a tight standard or loose depending on the reputation of the venue that sells the goods.
Another example of the standards is by Adorama (brick-and-mortar-storefront in NYC w/ large presence on Amazon/Internet). They sell a ton of refurb digi-cams on the 'net. While they state the condition of their refurbs and stand behind units with a 30-day-warranty they do not to my knowledge guarantee the unit's wear level. Of course, in digicams it's the wear and tear to the shutter, sensor, lens mech ...etc. that matters most.
If you, let's say arbitrarily pick other advertisers on Ebay, it's also random. By law, they have to state if it's refurbished but it's hazy as to how used a unit is after refurbishment. A refurbished digital camera can be 'near mint', light wear or even heavy wear marks. If a camera shows how many shutter actuations that's great; but until you get into DSLR level, you won't see that on P&S digi-cams.
At the risk of repetition, 'Refurbished' is not a clear statement of relative wear. And some advertisers are better about telling you the condition. So on Ebay, I go generally by the reputation or Ebay-er's consumer rating.
Can you see issues there with statement of 'Refurb' and 'Used' standards?
or have I just rambled on in the wrong direction?