A quarter struck on Dime Stock is not the same as a Quarter struck on a Dime Planchet. It means that the US Mint mistakenly used a stock sheet intended for Dime Planchets instead of the thicker Quarter Stock sheet. Here are examples. The labels give the description and weight..
I don't think it is Dime Stock but probably rolled on a thinner than normal planchet. As mentioned by @expat