The posts, which feature messages including “Do you make signs?” and “This is a sign”, carry no accompanying text except some curious emojis and a link to a newly created web page.

Rumours abound about what those sharing them could be up to. A message on the web page reads “If you're a UK or Ireland based signage manufacturer or installer then you won't want to miss this.” and encourages people to register their email addresses to be the first to know.