Ever wish you could summon a particular someone to take a look at an issue or pull request? Now you can:
When you @mention a GitHub username anywhere in the context of an issue or pull request, that person is notified and subscribed to future updates.
You can also now manage notification settings at the individual issue or pull request level. This lets you manually subscribe to any issue without commenting, or unsubscribe from issues no longer relevant to your interests:
Would you rather not be notified when mentioned? Disable @mention notifications in the Notification Center under Account Settings: