cc

 cc  is the pattern of mentioning someone in a public post to bring it to their attention, for example "/cc @username" at the end of a tweet. Evolved from the CC (carbon-copy) field in e-mails, and actual copies in physical mail.

pnut
pnut allows one to cc other users on posts by means of a /@username construct. The email notification settings on pnut allow one to choose whether or not to be notified about ccs.

Twitter
Random example tweet: @SwiftOnSecurity: Malwr/Payload/Deepviz sandboxes appear to fail to analyze this .JS file http://pastebin.com/raw/s7R9F7ir /cc @malwrhunterteam @MalwareTechBlog