Q:

The `dot` in username within first 3 character preventing from comment replies?

The dot(.) in username within first 3 character preventing from comment replies?
Because I never got replies from anyone else using that feature.

A:

Ooops, I misspoke in this answer. Apologies.
This was a long-standing bug of too-strict matching on @foo --  it now uses the proper valid username character set to match, [\w'\.\-].
Will be fixed in next deploy, within a few hours.

