We have "mid-level" permissions groups that generally have wide freedom to create/edit most fields, however this freedom sometimes causes confusion when a particular view (let's say a Timelog view) shows a field from a linked entity (let's say a Ticket). Showing the Ticket's fields is helpful, the ability to modify that field in Timelog view context can have unwanted repercussions. While this user needs permissions to create and edit both Timelogs and Tickets, changing fields on the Ticket while looking through the narrow view of a Timelog could affect other people's timelogs on that same ticket.
I've tried things like "coloring" linked fields differently with formatting to guide people away from these accidental changes, but it isn't fool proof.
It would be nice to have a global permission setting on a Permission Group that would not allow them to edit linked fields that they otherwise have direct permission to edit.