A custom form is just a detail screen that’s designed to act like a form and uses entry components linked to user specific columns as the temporary placeholders for the data. Once you are done filling out the form, you can have a button with a custom action that will first have an Add Row action that will take those user specific column values and write them to a different table. You can then follow that action with a Set Column action that will clear the user specific columns so it’s ready for the next time you fill out the form. It’s an alternative that many of us use in place of Glide’s native forms. There isn’t any official glide documentation regarding this. The thread I shared is the go-to thread to explain this. I recommend copying the app and taking a look at it to see how it’s set up in the builder.