Man in a yellow shirt looking stressed while using a laptop in a bright, modern room.

Recruitment for our intelligence services is famously selective, but a recently revealed - and some might say arbitrary - exclusion could rule out up to 1 in 5 UK adults from fulfilling the role of spy before they've even hit submit on their application. Tattoos (something 1 in 5 adults have), or at least tattoos visible in regular clothing (so those on the hands, face and neck), are an immediate bar for the role of mobile surveillance officer, according to a new job specification released by MI5 earlier this year (2015). In fact, the top skill listed in the advert was the ability to blend in, positioned above observation, driving, map reading and a number of other disappointingly mundane specifications, suggesting the spy department really is keen on their officers keeping a low profile.

The reason for the restriction on tattoos, the specification states, is that they would make a mobile surveillance officer easy to identify. For the same reason, men over 6 foot 1 and women over 5 foot 8 are also counted as ineligible for the role. This isn't the first time an MI5 job application has garnered a little more press than intended. In 2009, the department ruffled a few feathers when it placed an advert in the Times Educational Supplement in order to lure teachers away from their noble profession.

The advert read; "You may not realise it," the advert counsels, "but life has given you the skills you need to be an MI5 operational intelligence officer. "Your experience of dealing with people means you can build trust and relationships with all sorts of individuals, which makes you the ideal candidate for developing a career securing the information we need to protect national security."

Over the pond, our friends in the CIA also take a rather open approach to their recruitment process. Since the dawn of social media, the Central Intelligence Agency has found it impossible to prevent failed applicants from revealing details from the recruitment process online, so they've elected to make the process as public as safety permits. One surprising revelation to come out of this is how they handle counter-espionage suspicions in applicants. The CIA's head of recruitment, Ron Partick, told Forbes Magazine;

This will quite blow people's myths about the CIA, but one of the ways we ask: Are you connected with a foreign government? Do you have relatives working for a foreign government, or do you have any connections or allegiances that may be a conflict if you were working for the CIA?

So there you have it, no tattoos in the UK, and if you want to spy on America for another country, don't answer yes when the CIA asks you about it. 5 weird facts about our intelligence agencies:

    Despite the obvious dangers of spy work, MI5 claims to work within the law and health and safety law. They were recruiting for a new head of health and safety in 2013, at a salary of £60,000 per year. The only catch was that they wouldn't tell applicants anything else about the role.
  • Much of MI5 operatives' equipment is classified and, no doubt, high-tech. This is why it surprised many when, in 2006, Russia accused British spies of concealing a covert listening device inside a fake rock and placing it on a Moscow street. Even more surprising was that this allegation turned out to be true.
  • MI5 has a secret Northern Operations Centre, but it doesn't say where it is. However, speculation about an MI5 facility just over the road from the BBC's new home at Media City, Salford, is quite intense.
  • The paradoxical approach to intelligence referred to as known unknowns is true and is being increased. The MI5 director general Jonathan Evans said in 2009 that one of his priorities is "to try and know more about the people we already know about, rather than to find the people we don't know anything about. It would be nice to know about the unknown unknowns, but it is probably a less rich seam than knowing more about the people we know are a threat to us.
  • One of the biggest recent threats to intelligence data held by British services wasn't hacking or deliberate leakage but the dodgy British weather. The floods of 2007 near Cheltenham caused a water shortage at GCHQ, meaning vital computer cooling equipment couldn't function correctly, causing a bit of a panic, although no data was lost.