1. Oracle NetSuite Help Center
SuiteAnswers: "Setting Display Options for Fields on Custom Forms" (Answer ID: 9911).
Reference: In the section detailing Display Type options
the documentation states: "Inline Text - The field appears as text and cannot be edited." This directly confirms that setting the display type to "Inline" causes the exact behavior described in the question.
2. Oracle NetSuite Help Center
SuiteBuilder Documentation: "Fields Tab on Custom Forms".
Reference: This documentation outlines the properties available for fields on a custom form. Under the Display Type setting
it lists "Inline Text" as an option that makes a field read-only
preventing user interaction while still displaying its content. This is distinct from "Hidden" (not visible) or "Disabled" (visible but grayed out).