Derived sites are sites that use ‘library themes’ or ‘public themes’. These themes were not custom made for a particular site or client, but have multiple sites that use that theme. It is important to remember that the source theme can push updates to all derived site themes. These updates override the existing theme files, content types and content fields. If you use a ‘library theme’ for your site, you can choose to unlink it from parent theme updates. However, if you want to use the parent theme’s updates, while still being able to change your derived site’s theme, there are a few things you can do:
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If you are creating a library theme or public theme, keep the following best practices in mind: