I've received 10% off when ordering DVC merchandise like the Alex & Ani DVC bracelet. There was a link on the DVC site to take you to the store which I believe the way the discount worked.
You can get a 10% DVC discount through the Shop Disney Parks app if your account is linked correctly to your MDE account that shows you're a DVC member.
You have to use a link to get the discount on the DVC store online. I could only find it with the Alexi and Ani bracelet offer on the MS website. Recently I used my Disney Visa discount instead as I could still enter a code for that one.