Anorak button

A special button on the remote control for internet-enabled TVs which records - when pressed - the channel, programme, time and date, along with a few seconds of video. It then contacts the broadcaster and sends a message that a viewer has spotted a mistake.

The viewer then receives an email response from the broadcaster allowing them to point out (in excruciating detail) the error they have spotted; anachronisms, costume inconsistencies & mistakes, patterns of speech, errors in the Periodic Table*, and worst of all, errors of detail concerning aircraft, weapons, and steam railway locomotives.

Broadcasters should expect to receive messages along the lines of "Dear Sir, in the episode of Poirot referred to, the locomotive was clearly as Great Western "Schools" class, yet the protagonists were allegedly journeying to Norfolk, served by the L.N.E.R.; the carriages were incorrect, being post-WW2 Southern region stock; the porter's barrow shown on the platform of the arrival station was of a type not produced until some five years after the date of the alleged events, and for the L.M.S.; and the Station Master's cap had the wrong number of bands of silver braid, indicating that he was actually a Traffic Inspector. I trust that you will immediately refer this to the production team, and that those responsible will be tortured and then shot** without trial. Yours, Kenneth Blathergood".

*The reader's attention is drawn to a particularly disturbing episode of "Endeavour" set in the 1960's where in a scene in a Chemistry Laboratory a Periodic Table chart in the background clearly showed a number of Transuranic elements not discovered (or indeed created) until two or three decades after.

**Other means of execution are acceptable. The important thing is that they die for their sins.