I left out one very important thing, so I'll cover it here.
If you add ms-hide to an element, MemberStack will remove that element from the page entirely. It's a great way to add some security to your site if you'd like to include premium assets. That said, ms-hide is not bulletproof. We do not recommend you post sensitive, personal information directly to your Carrd site.
If you need to collect, store, or display sensitive information in Carrd, you'll want to upload that information to MemberStack.