informalinclude

Informalinclude is a directive used in some templating languages, particularly within wiki environments like MediaWiki, to conditionally include content from another template. Unlike standard template inclusion, which always inserts the entire content of a specified template, informalinclude allows for more granular control. It typically works by checking if a certain parameter or variable is present or has a specific value. If the condition is met, the content of the target template is inserted into the current template's output. If the condition is not met, the content is omitted.

This functionality is useful for creating templates that can adapt their output based on context or user input. For example, a template might have a default display that can be modified or supplemented by including additional sections only when a particular parameter is set. This avoids the need to create multiple, near-identical templates for slightly different use cases. The "informal" aspect refers to its less rigid nature compared to mandatory inclusions, offering flexibility in how and when template content is integrated. It can simplify template design by allowing a single template to serve multiple variations of a display or functionality.