Deletes an issue type scheme. Only issue type schemes used in classic projects can be deleted. Only issue type schemes not associated with a project can be deleted A validation error will be returned if the specified scheme is associated with one or more projects. Use [Get issue type scheme API](https://developer.atlassian.com/cloud/jira/platform/rest/v3/api-group-issue-type-schemes/#api-rest-api-3-issuetypescheme-get) (with the projects expand, and id query parameter) to get a list of projects. Then, use [Assign issue type scheme to project API](https://developer.atlassian.com/cloud/jira/platform/rest/v3/api-group-issue-type-schemes/#api-rest-api-3-issuetypescheme-project-put) to associate all projects to another scheme before deleting. **[Permissions](#permissions) required:** *Administer Jira* [global permission](https://confluence.atlassian.com/x/x4dKLg).