Which rule governs the design of user interface screens in international standards?

In international standards for designing user interfaces on screens, including Android, the main rule is to adhere to the principles of humane and accessible design, as well as flexibility and adaptability of the interface.

One of the key standards is Material Design by Google, which provides recommendations on the placement of elements, colors, typography, and interaction.

Additionally, an important rule is to follow global standards of localization and internationalization (i18n) to ensure the interface displays correctly for different languages and cultures.

Overall, the design is governed by the following principles:

• Clear hierarchy of interface elements.
• Use of standard components and patterns.
• Adaptability to different screen sizes and orientations.
• Accessibility for users with disabilities.

For Android, this is reflected in the official Material Design documentation and UX/UI guidelines.