By Nikki Bayley
Heading to Rome and planning on visiting Vatican City and St Peter's Square? Then make sure that along with your camera and sun cream, you also pack a shawl, shirt and some long trousers - or face being banned.
The Vatican City's Swiss Guard stepped up security in St Peter's Square last year, demanding that visitors who are dressed 'inappropriately' cover up. That means shorts, short skirts and bare shoulders are no longer allowed. The clothing ban was always in place at St Peter's Basilica, but was last year extended to the entire square. This led to hawkers setting up, selling scarves, paper trousers and shirts - and the square turning into a changing room.
To save you the embarrassment of sporting pull-on paper trousers, here's our guide to clothing customs around the world...
Barbados - Don't wear camouflage clothing
Several Caribbean nations have this rule, it's similar to not being allowed to impersonate a police officer in the UK. To stay safe, it's a good bet to leave any khaki, camouflage or military-style clothing at home. Military-style clothes are strictly for the professionals and wearing combat gear will almost certainly result in you being sent back to your hotel to change and could even land you in jail.
[See also: Places you're not allowed to visit]
India - Don't wear shorts
Men and women should avoid wearing shorts in India as there is a stigma attached to Western adults wearing them. Shorts are seen as the uniform of the poorest people in Indian society and also - for men - they are traditionally just for young boys. Creased clothes should be avoided too - Indians are fastidious about their appearances, so take advantage of street ironing booths, or hotel laundry and ironing services, to avoid causing offence.
Peru - Don't wear a red hat if you're a single man
The people who live on Taquile Island on Lake Titicaca are textile experts, and they have used this skill to develop a rather handy shorthand when it comes to spotting who's single and who's attached. The men of this society wear knitted hats: a red hat says that you're married, and a white one shows that you're single. There are a few different ways to wear your hat if you're not attached; if your hat tilts to the right, you have a girlfriend, to the back, you live with someone but if your hat tilts to the left, you're single and available!
Indonesia - Don't leave your shoes pointing in the wrong way
Indonesia is a fairly conservative country. Away from the beach and tourist areas, women should always keep their knees and shoulders covered and men should avoid wearing shorts. When visiting Hindu temples, always remove your shoes but make sure that the toe of the shoes points to the outside from inside the entrance.
Morocco - Don't put your swimsuit on while you're on the beach
As a Muslim country, you should follow the usual rules of public behaviour - no bare knees or shoulders - and if heading away from tourist areas, dress more modestly with legs covered too. On the beach in a tourist resort, bikinis and swimming costumes are fine, but you should always head to a changing cabin when getting in or out of beachwear.
Cayman Islands - Don't go topless
Although the Cayman Islands are famous for their stunning beaches and warm turquoise sea, don't be tempted to get an all-over tan, as going topless or completely naked is illegal and strictly enforced. So cover up!
Iran - Don't forget your hijab
OK, so you're probably not heading to Iran for holiday but, just for the record, all women and girls over nine years old must cover their hair and most of their body. Most women choose to wear a chador, a full-length cloak that covers the whole body, along with scarves to cover their hair and neck. Western women should wear the hijab, a headscarf and clothes which cover everything, so only your face and hands are visible.