Reuse controls without losing meaningful states
A color palette or component screenshot is only part of a system. The useful contract also explains when to use a control, what its labels mean, how it works with different inputs and who updates it. Reusing a broken pattern consistently does not make the experience effective.
Illustrative state inventory:
| Component | States to document |
|---|---|
| Add-to-cart button | Available, loading, unavailable, failed |
| Enquiry field | Empty, focused, invalid, corrected |
| Product card | Image missing, item unavailable, long title |
The shared component owner records expected messages and behavior for each state. A change to the button’s loading rule is reviewed on product pages and quick-add cards, because both use the component in different contexts.
Document who maintains shared components
A reusable component can support accessibility, but adopting a library does not certify the finished website. Content, configuration, page composition and later customizations still matter. The GOV.UK Design System is a useful example of documented styles, components and patterns, not an Amadeus visual template.
Next, inventory the controls on one buying journey, document the missing states and assign a maintainer. Test a shared change in every important context before treating it as ready for reuse.
Website field guide · Website design and development services · Website accessibility
Reference: GOV.UK Design System: styles, components and patterns. Checked November 4, 2026.