I have always used rice wine vinegar when a REC calls for it & rice vinegar when it is stipulated.
To me they taste very different. I can only find rice wine vinegar in an oriental grocery store.
I just found the following at 'chowhound'==>
Punkysdaddy Feb 23, 2016 06:20 AM
I can not understand it when people say they are the same thing. Taste them, Please. Rice wine vinegar is mild, very smooth, and very hard to get for a very good reason. Rice vinegar is tart, puckery to the tongue, even crass. Hokan is the best inexpensive brand but is almost impossible to find for a very good reason, the price of sake. Until about six years ago rice WINE vinegar was very prevalent on any market. Now because the of the price of sake, the market uses the sake for wine and does not let it go to vinegar. Hence a shortage of rice WINE vinegar. If you take ANYTHING, anything, mash it up, and let it sit it will go straight to vinegar. Example: Apples; mash them, add water and let it sit, eventually you will get vinegar. Take any wine, open the bottle, let it get to room temperature, and it will turn to vinegar. The difference is what happens in between, the alcohol goes away in the process and what you have left is a great wine vinegar. Saying rice wine vinegar is the same as rice vinegar is like saying red vinegar is the same as red WINE vinegar. You know they are different. If you use cheap rice vinegar instead of rice wine vinegar you will ruin any pickle you make. I make a lot of oriental style pickles (Daikon) and rice vinegar makes the texture mushy. Also, the key here is acidity, rice wine vinegar is only up to 3%, rice vinegar is as high as 5%.