• English players are allowed to fly their families over as long as they don't interfere with training.
• Brazil and Mexico warn against overly frisky "acrobatics".
• Spain demands no funny business the night before matches.
• Australia, France and the US are all allowing a bit of action during the competition, to varying degrees.
So why all this fuss over sex before sport?
English football agonises over its national team. The two principal competitions it enters -- the European Championships and the World Cup -- are perennial disasters. Each failure is marked by mishap. In recent decades, players have been sent from the field, suspended, robbed by refereeing, missed penalty kicks and cheated by Diego Maradona's "Hand of God" goal in the quarter-finals of the 1986 World Cup.
The 2006 World Cup finals in Germany offered a new explanation. The press constructed players' Wags as distractions from their partners' mission.
With the emergence of sexology and internationally competitive sport in the 20th century came scientific claims about sex and performance. Cyclists and swimmers ingested liquid extracts from bull testicles a century ago, and the last English FA Cup final before World War II was allegedly decided on the strength of which team took monkey gland tablets in training (the losers).
Today's story is a blend of mysticism, media gossip and minor scholarship. Indian wrestling requires men to forgo sex to capitalise on the semen they produce.
There are loads of great sporting achievements that followed nights of denial:
• Khalid Khannouchi's marathons.
• Muhammad Ali's fights.
• The 1996 Canadian Olympic swim team.
Mike Ditka's Chicago Bears.
These are contrasted with great performances that come hard on the heels of nocturnal indulgence:
Wilt Chamberlain's 100-point basketball game.
Bob Beamon's Olympic long jump.
Brazil's 1994 World Cup victory.
Kerrin-Lee Gartner's Olympic skiing gold.
Consider the mythology that swirls around the 1974 World Cup final between the Netherlands and the then Federal Republic of Germany.
The Dutch were supposedly instructed to have sex the night before. Having scored in the first minute, they flagged. The Germans, ordered to abstain, triumphed, courtesy of two late goals.
So the myth continues. The scientific evidence is sparse. This obsession stems from history and culture.
Sex and sport have a lengthy shared past. In Ancient Greece and Rome, the capacity to channel desire into athletics proved men's fitness to rule society.
The capacity of sport to incarnate such masculine hegemony is being destabilised as more women become spectators, journalists and athletes. Over the past 20 years, sports have sought them out as consumers, and increasing numbers participate as athletes.
But the political economy of women's spectatorship is not matched by the political economy of women's sport. Media attention and gossip consign elite sportswomen to a different sphere from elite men. And as spectators, their expertise and commitment are rarely foregrounded or respected.
So among hundreds of media stories that fetishise Wags (no one at the World Cup is overtly gay!), their bodies and romantic histories will be guides highlighting "selfies, shopping and skinny mojitos".
Clearly, as long as women are routinely valued for their looks and the men they accompany, and conventionally devalued for their other qualities, the Wags charade will come around every four years.
• Toby Miller is professor of cultural policy studies at Murdoch University, Perth.
