Is mocking people without specifying them punishable?

Mocking others is a reprehensible trait that is not permissible for a Muslim. However, mentioning a story that diminishes an unknown person does not entail sin and is not considered backbiting, as it is authentically narrated from the Prophet, peace and blessings be upon him, that he used to say, "What is the matter with people who said such and such?" Backbiting occurs only with specific designation, or with ambiguity when the listeners know the intended person.