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You can create a real component from JIRA's own "Project Component" screen or directly inside the Subcomponents screen. To create a subcomponent inside the Subcomponents screen press the Create Component button next to the "Create Folder" button.
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A new dialog will be opened which allows you to enter project component attributes. Other than the project component name all other attributes are optional.
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Creating a component this way also adds this component to JIRA's own Component list. Even if you uninstall the add-on later the created component will remain. Actually, this is a just shortcut for creating actual JIRA project components. The new newly created component appears both in the Subcomponents page and in the JIRA itself.
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