A.9. “error_uri”语法 ==================== “error_uri”元素在[4.1.2.1](../Section04/4.1.2.1.md)、[4.2.2.1](../Section04/4.2.2.1.md)、[5.2](../Section05/5.2.md)和[7.2](../Section07/7.2.md)中定义： error-uri = URI-reference