WordPress displays font sizes differently based on quantity. Five or fewer sizes get the visual “t-shirt sizing” interface (XS, S, M, L, XL), while more than five shows a dropdown list.
Align your font size names with WordPress conventions for consistency across themes. Use “Small,” “Medium,” “Large,” “Extra Large” etc. even when you have more than five sizes. This creates familiarity for users and maintains ecosystem standards.
Always order font sizes from smallest to largest in theme.json – the interface displays them exactly as you’ve ordered them. Proper ordering creates intuitive user experiences and follows established design patterns.
Following these conventions makes your block theme feel native to WordPress and creates better experiences for both developers and end users.