Compare the rule with concrete cases
Fictional parent has paper=A4 and margin=20 mm. Child overrides paper=Letter but inherits margin. Its effective pair is Letter/20. Changing the parent margin to 25 changes only its margin; changing parent paper to A3 does not change the child’s explicit Letter.
| Property | Parent | Child mode / value | Effective |
|---|---|---|---|
| Paper | A4 | Override / Letter | Letter |
| Margin | 20 mm | Inherit | 20 mm |
| After parent margin edit | 25 mm | Inherit unchanged | 25 mm |
Work through the distinction
A record-level “custom” flag would leave the margin’s source unclear. Per-field modes allow one explicit choice alongside a changing inherited value.
After both parent edits, what is the child’s effective pair?
Show the worked answer
Letter and 25 mm. Paper keeps its override; margin follows its parent.
Acceptance wording to adapt
Resolve paper and margin independently using each property’s mode. Parent edits must affect inherited properties only and must preserve unrelated child overrides.