Web resource dependencies
Unsure about entity vs. table? See Developers: Understand terminology in Microsoft Dataverse.
The dependency is only established after it is configured and the web resource is published. Dependencies for unpublished web resources will not take effect until the web resource is published.
Before this feature you would need to manually add the column to the form and then configure the control to be hidden. Now you can establish this dependency more directly and eliminate the possibility that someone will remove the hidden column from the form.
Create accessible web resources
Webpage (HTML) web resources
Script (JScript) web resources
Image (JPG, PNG, GIF, ICO) web resources
Stylesheet (XSL) web resources
Data (XML) web resources
CSS web resources
RESX web resources
Web resource table reference
Sample: Pass multiple values to a web resource through the data parameter
Sample: Import files as web resources