Glastonbury Festival goers have been warned they could be banned from travelling home by train if they are too dirty.
First Great Western, the only train operator which visits Castle Cary station near the festival site, said it has issued the guidance for the festival every year.
Passengers are also advised not to bring wheel barrows with them to the festival, which sees tens of thousands of music fans gather in Somerset.
On Thursday night Wolf Alice and Drenge took to the stage and the Dalai Lama has announced he will be making an appearance on Sunday to mark his 80th birthday.
The visit ahead of his birthday in July will be to spread his message of "compassion, non-violence and the oneness of humanity".
Russian punk band and activists Pussy Riot are due to appear at the event today.
The band's members were released from a Russian prison last year after 21 months.
But in a special leaflet printed for the five-day event, First Great Western has warned mucky music lovers they may be turned away if they are too dirty.
The leaflet said: "In the interests of the comfort of all our customers, you will not be allowed to board the train if you are excessively muddy."
The leaflet which has been produced since 2013, provides 12 pages of guidance and includes advice that passengers may not be allowed to board a service if excessively dirty.
The spokesman for First Great Western said: "We produce guidance each year for passengers travelling to Glastonbury.
"That advises people against bringing wheel barrows, reminding them to charge their phones, reminding them to bring a young person's rail card."
He added: "We've also worked incredibly hard with Glastonbury to produce extra services to take passengers to the festival.
"One of our team provides guidance which they do every year.
"That guidance also includes a sentence that says passengers who are excessively muddy will not be allowed to board.
"In the same way that a pub will prevent people from buying alcohol if they have drunk too much alcohol.
"It's advice requesting that people show due consideration to their fellow passengers. We recognise that people at festivals get muddy."
Asked what constitutes "excessive" mud, the spokesman said: "We all understand it's a festival and it is a farm... it means excessive".
He added that a boot wash facility and a 'mud removal area' would be available at Castle Cary station for muddy passengers.
Among those performing at the festival are Florence and the Machine, Patti Smith and The Who.
Festival goers have been enjoying warm and dry weather but rain is forecast for Friday.