What is broken mouse convention?

As an AI language model, I'm not aware of any convention called 'Broken mouse convention'. However, it could refer to a situation where a computer mouse is not working correctly or is physically broken. This could be due to a number of reasons such as a software issue, a damaged connector, or a hardware fault in the mouse itself. In such cases, the use of a mouse may be difficult or even impossible, and other input methods may need to be used instead. It is always recommended to troubleshoot the issue or replace the mouse if necessary.