Hashtag is the internet’s lingua-franca for the # symbol and is used on the micro-blogging site to collate topics and trends.
But it becomes the latest anglo invader to fall foul of strict French Government lingual purists who seek native replacements against insidious Anglicisation.
Perhaps unsurprisingly the decree received a frosty reception on Twitter. Some revolutionary French tweets vowed to defy the authorities, others met it with the 140-character equivalent of a Gallic shrug.
A vocal group of pedants even launched a counter-campaign, insisting dièse is incorrect and should be croisillon. A dièse, they claim, is the slanted character in musical notation and not the straight-backed hash used on Twitter.
It is not the first time the French government has tried to hold back the irresistible tide of technical jargon from polluting la langue de Voltaire.
Previous meddling insisted on courriels instead of emails and that inboxes should be purged of le pourriel, electronic rot, instead of Spam.
Even more unsuccessful was its insistence of the word l’arobase, in favour of at, when spelling an email address.
David Abiker, a satirical French columnist with over 75,000 followers on Twitter, believes the Government should go even further. He suggests replacing the English acronym WTF (used to signify jaw-dropping content) should become "Ça restera dans les annales", loosely, this is going down in history.
A little graphic I created to help me remember the new name
The hashtag ban was issued this week in the official Government journal by the Commission Générale de Terminologie et de Néologie, which works alongside the Academie Francaise to enrich the French language.