Gmail - muted feature

Been using gmail for some time and never seen this before. Anyone know what it means/does?

It just appeared when I got a reply to an email from "Alison" and says "Muted" next to the preview of her reply. When I open the email fully there is no further detail and the word "muted" isnt to be seen.

 

Annoying feature...figured it out. If anyone is interested then here's the deal.

http://mail.google.com/support/bin/answer.py?answer=6594

http://mail.google.com/support/bin/answer.py?answer=47787

 

Lines - "I will always use the help feature/Google before posting"

 

In this case, yes, as it was a Google feature. As I know you are very aware, Google is not the answer to ALL tech questions as some understanding of the problem is often required to come up with a relevant answer In this case Google was very relevant