Looking for a NP-85 battery?

At this point they are next to impossible to actually find. Yea, they'll tell you they got it but when you get the shipment it's something less than what you ordered.
What's the difference" The 2000mAh represents the maximum service life per battery charge. At this point in time the 2000mAh battery is the max you can reasonably expect to get. 1900 is less of a performer than 2000 and 1750 is less than 1900 and so on.
Most tech savy have figured this out and won't settle for anything less, the retailers, those that actually had the item on the shelf, have run out of the actual item and many of those that definitely know better are even pushing past the legal definition of "false advertising" to get "SOMETHING" out the door. I expect that they're hoping that you either won't notice or won't actually sue, this btw, is a FEDERAL offense that you could actually do time AND a fine for. One or two of you will probably not be able to afford a FEDERAL suit but five or more will find it in range of your pocket.
It will probably be several weeks or a month or so before any 2000mAh battery is actually on the shelf and when it does it's a bet that the $4 -5 price tag per will be relaced by something near twice that. If the asking price is above $12 per, keep your money in your pocket, at least in your bank account, or in your old sock, whichever applies. (The $12 is a bit overboard but allowable if you're really that desperate.)

I think that most false advertising laws do allow for some level of approximation, even if it favors the advertiser.

Also, if I had a dime for every time I bought some tech that didn't live up to specs, I would be a rich man. I have quite a bit of experience with batteries, and I must say that the mAh charge capacity values are nothing more than ball-park figures.

Another thing to consider is that the charge capacity that is generally quoted for batteries is the total charge capacity, not the useful charge. That means that the figure is the amount of charge you could extract from a fully-charged (and brand new) battery if you were to discharge it completely, called a "deep discharge", which will leave the battery completely useless (cannot be charged again after that, if it even survives the deep discharging process without bursting). The actual usable capacity of the battery is usually about 50% of what is quote on the label.

Also, have you considered the possibility that the battery that used to be labeled as 2000mAh is actually the same as the one that is currently labeled 1900mAh? It is possible that the company was originally giving an inflated figure, and got a slap on the wrist (e.g., lawsuit or complaints) and readjusted the label to a more accurate figure.

There is also a possibility that the company can no longer produce this battery due to regulations that prohibit it. Regulations on batteries are very strict and have been evolving quite a bit with the years. Required safety margins and protective coatings have increased quite a bit in various places, and it is very possible that the 2000mAh version of the battery was simply packing too much capacity for too little protective measures, and they simply had to pull the product to keep up with the regulations and be able to sell them.

In short, don't get all riled up for a 5% capacity reduction (from 2000 to 1900). And btw, in case of a lawsuit, that is probably what the judge is going to say too. And, if anything, you should complain to the company or inquire as to why they pulled that product, they might have a very sensible explanation.

To start with, this was posted as an fyi, not a query or complaint.

Charge capacity, REGARDLESS OF TYPE OR RATED CAPACITY, should be very near rated capacity and NOT 50% thereof. If it’s only that then it’s a piece of junk and should be disposed of accordingly.

Will more be produced? Maybe not, but more likely, due to public demand and the fact that it already has been (which includes legalities), more will be produced . . . . eventually.

If the "packaging" was under rated then the actual manuf. should have said so, AND, they didn't! Like it or not it’s their responsibility.

I'm a retired heavy duty mechanic and have serviced a wide variety of equipment engines and motors which means I do not need a lecture on the technical or legal issues involved.

My demeanor is my affair, not any one else’s. If someone wants to take umbrage, they're quite welcome. The U.S. government already did, and lost.