# General constraints
Rules that belong to no single box, checked on **every** review rather than only
when a matching box is touched.
A box's constraints live with the box. These are the ones that would otherwise
be written into whichever box happened to notice them first — and then never
read by a review of the box that breaks them.
## Topics
- [No knowable rework](no-knowable-rework.md) — the final shape of what's
needed now.
- [Surface area arrives with its consumer](surface-arrives-with-its-consumer.md)
— a Markdown extension, layout, CLI flag, config field, extension hook or CSS
hook is added only when something in the repository needs it.