The announcement was made on Facebook at the weekend and picked up by Awkwardmessages.com where, underneath the photo of a baby girl, a caption reads: "Hashtag Jameson was born at 10oclock last night. She weys (sic) 8pounds and I luv (sic) her so much!!!!"
However, it isn't clear whether the bizarre name is real, a joke or part of a viral marketing campaign (in which case, if it's the latter, more fool us gullible mugs!).
Besides, Hashtag is for Twitter, surely, so why announce it on Facebook?
Still, its lack of verification hasn't stopped social networkers wading in to offer their opinions on the name. Some said it was ridiculous while others said it was a reflection of modern times.
One commented: "The day she turns 18, she'll change her name and kill her parents. Not necessarily in that order."
But credit where credit's due: as ridiculous names go, it's pretty good, though perhaps not as ingenious as the Israeli couple who named their daughter after a feature on the social networking site Facebook.
The girl was called Like, after a button that allows users to express their approval of photographs, links and status updates.
Here at Parentdish, we quite like Hashtag, though would prefer its less long-winded and more correct form: #