Trying to convey sarcasm without offending the recipient can be tricky with online communication methods, but a US company thinks it has a solution.

The "SarcMark" is being introduced as a way to imply sarcasm in the same way a question mark is used to add a querying tone or an exclamation mark is used to indicate strong feelings, surprise or even shouting.

The suggested use for the SarcMark is to stick it at the end of a sarcastic sentence or comment in order to avoid any misunderstandings over the tone of the missive.

The symbol – described by The Telegraph as "a dot inside a single spiral line" – can be used on PCs, Macs, and some mobile devices and is conjured up by pressing the control key and the full stop button.

The symbol costs $1.99 to download which seems like really good value... now where are those  control and full stop keys?