Tip of the Iceberg

Category domino
Strictly speaking, Notes doesn't support nested controlled access sections, so this is on a "use at your own risk" basis.

Periodically I identify a need (or receive a request) to prevent editing of specific fields on a document under conditions that differ from the conditions under which the rest of the fields should be editable. Depending on the form layout and quantity of fields involved, sometimes it's just easiest to add a line under the field and insert computed text that displays the field's value, then set the field to display to editors and the text to display to non-editors. But in a more complex scenario, the "cheapest" approach is to use nested controlled access sections.

As I mentioned, Notes doesn't officially support this feature: if you highlight content that already includes a CAS (or is within one) and try to create another, the option is disabled. However... if you create a temporary form and define the new section and its content there, then copy and paste it inside of a CAS on the existing form, the edit restrictions behave precisely as one would expect: the conditions for each inner section override those of the parent section. I've used this approach in versions 4,5,6, and 7 of Notes, and so far it's always worked reliably.