What is required in order for a themelet to be used globally?

For a themelet to be used globally within Liferay, it must be installed in a theme. This is essential because a theme acts as a container for various components, including themelets, and it defines how those components are rendered across the site. By ensuring that a themelet is included in a theme, you can guarantee that it will be accessible and applied consistently throughout the Liferay instance, enabling a cohesive design and user experience across multiple pages or instances of the site.

Contextually, while visibility in the Liferay control panel might suggest that a themelet is recognized, it does not inherently mean it will function uniformly across all necessary areas. Creating a themelet using FreeMarker is a common practice, but it is not a requirement for global usage; themelets can also be developed with other templating strategies. Lastly, having a public API refers to how the themelet interacts with other components but does not directly relate to its global applicability. The installation as part of a theme is the critical factor for enabling a themelet's full functionality across the application.