Acting on behalf of Subaru Corporation, the parent company of Subaru of America Inc., an attorney filed Wednesday with the United States Patent and Trademark Office (USPTO) for a trademark on the name "S209" as pertaining to "automobiles and structural parts and structural fittings therefor" as well as "floor mats for automobiles."

A trademark filing on the behalf of Subaru suggests a more powerful, limited-production WRX STI may be on the way to the United States.

S209 in the context of Subaru models calls to mind limited-production variant of the WRX STI sports sedan sold only in Japan. For the 2012 model year to celebrate the departure of the previous generation of WRX STI, Subaru built the S206. It followed up for the 2017 model year with the S207, and the 2018 model year with the S208. All of these were available solely in Subaru's home market of Japan, though the stateside filing for the S209 name opens the possibility that the next installment in the S20X line may also be sold in the United States.

So if Subaru is planning a WRX STI S209 for sale in the Americas, what can we expect of it aside from special, embroidered floor mats? All of the following is speculative, but plays within the confines of the previous (and numerous) limited-edition WRX and WRX STI models, so none of it will be territory unfamiliar to Subaru.

One reasonable starting point is that of the S208, which added a carbon fiber roof and aero elements, retuned suspension, and an extra spoonful of horsepower to the WRX STI. At least 310 horsepower and a widened torque band are possible in the S209, as those are what we got from the 2018 WRX STI Type RA, which also featured enough carbon fiber to cover up Rhode Island. As long as one plays in the realm of possibility, one can fantasize that the S209 may get some of the power-raising parts from the (still Japan-only) WRX STI TC 380, but U.S. emissions requirements may count these upgrades out.

The S209, if Subaru builds it, will only add to the ever-growing and confusing list of special WRX and WRX STI models built from the current generation of WRX. In the United States, we saw the Series.Gray and Type RA, Canada had the Raiu Edition, South Africa the Diamond Edition, and Japan the S207, S208, Type RA-R, and TC 380. With the aging WRX reportedly due for replacement in 2020, Subaru seems to be giving the current car no shortage of last hurrahs.

Availability of the S209 may be similar to that of the S208, whose Japanese buyers were selected via lottery after putting in a short application. Production would likely be 500 units or less, as the S207 was limited to 400 cars, and the S208 to 450.

The Drive contacted Subaru for comment on its trademark and the likelihood of selling a WRX STI S209 in the United States, and we will update when we receive a response.