The 'ID card challenge' asks Iranians who they really are

Image copyright kartmelichallenge Image caption Young Iranians are posting pictures of themselves along side their official ID card photos

Young Iranians are using photos on Instagram to show who they really are - alongside the formal pictures they've had to take for state ID cards.

Two popular Instagram pages have been asking Iranians post these photos - and many are embracing the "KarteMeliChallenge" ("national ID card challenge"). The black-and-white, expressionless ID photos stand in stark contrast to colourful, fun, style-conscious snapshots that people have put up to show what they are actually like.

Since it started a week ago, 100 snapshots have been uploaded - in a country where posting private photos on a public platform can be interpreted by the authorities as criminal acts. A second page "DontJudgeChallengeTM" has 160 more photos - but many more seem to be inspired by it, with 120,000 clicking the follow button.

Image copyright kartmelichallenge

Image copyright kartmelichallenge

The authority in charge of issuing identity cards and passports in Iran gives the following photo guidelines on its website:

"For men : no hats, glasses, neck ties, jewellery, styled hair or sideburns... the forehead and ears should be visible. The colour of clothes should not match the background."

"For women: a full hijab; using a plain dark-coloured headscarf so the round shape of the face is visible, no make-up or jewellery."

Follow BBC Trending on Facebook

Join the conversation on this and other stories here.

Most of the comments on the Instagram account revolve around the appearances of those in the photos, with many being sarcastic about those who seem to have undergone cosmetic surgery - which is extremely popular in Iran.

"The challenge should have probably been dubbed as before-and-after [plastic] surgery," one commented.

"Before proposing to a girl ask her to send you a copy of her ID card to you; then you will not need to waste too much money on flowers and sweets!" a Facebook user suggested.

Image copyright kartmelichallenge

The administrator of the original KarteMeliChallenge page earlier tried to lead a different campaign in which she had asked women to share photos with Islamic headscarf along with one without it, a drive resembling the viral My Stealthy Freedom campaign which encouraged women to throw off the hijab.

However she later decided to focus on a new idea. "It's rare for people to be happy with his or her photograph on their ID card," she told the website IranWire, "and this is what makes the campaign interesting."

There has been a strict dress code in place in Iran - particularly for women - since the 1979 revolution, and the response to the challenge seemed at least partially motivated by people wanting to express their true identities.

One Facebook user described the challenge as a demonstration of "the public-vs-private persona."

"I had never imagined sharing my national ID card online," said another.

Next story: After British man abused, Taiwan debates its hidden racism

Image copyright Christopher Hall

Many people in Taiwan thought racism and prejudice didn't exist in their society - until a viral video of a British man and his Taiwanese girlfriend being verbally abused on the subway touched off a huge debate. READ MORE

You can follow BBC Trending on Twitter @BBCtrending, and find us on Facebook. All our stories are at bbc.com/trending.