Https://community.kde.org/Get Involved/design/HCI/Checklists/Fonts
Appearance
Text and Fonts
1. Fonts in the user interface
- Application usage of fonts should follow the global KDE settings (exception: fonts within documents, special artwork in games)
- Application settings for fonts should be relative to the KDE settings
- Font family: The KDE setting should be used by default (special text like titles can use a font style relative to the standard setting)
- Font sizes: The KDE setting should be used by default (special text like titles can use a size relative to the standard setting)
- KDE standard widgets should be used to modify font settings in applications
2. Spelling
- There should be no spelling mistakes (US English)
- There should be no spelling mistakes in the translations, either
- Book title capitalization is used where appropriate
- Sentence style capitalization is used where appropriate