When is it and is not it acceptable to display a political banner at the World Cup in Qatar? The answer seems to depend largely on the political message, with fans criticising what they see as inconsistent enforcement of FIFA rules by the host country.
The first World Cup in the Middle East has been anything but insulated from the troubles of the volatile region, set against a backdrop of anti-government protests in Iran and an upsurge in Israeli-Palestinian violence.
But while airing pro-Palestinian sympathies has been allowed - people were even handing out "Free Palestine" T-shirts ahead of Argentina's match with Poland on Wednesday - security forces have clamped down on fans seeking to show support for protesters in Iran, who have been demanding an end to clerical rule there.
The contrast was laid bare this week outside the Al Thumama stadium. On Thursday, security ushered through hundreds of fans draped in flags, hats and scarves showing support for Palestine ahead of the Morocco v Canada match.
Two nights earlier, security at the same stadium confiscated items showing support for Iranian protesters, forcing fans to remove T-shirts and some flags ahead of Iran's crunch match against the United States.
As crowds dissipated after Iran's 1-0 defeat, Reuters journalists saw guards chase men in activist shirts through the stadium precinct, tackling one to the ground as he screamed the cry of Iran's anti-government protesters: "Woman Life Freedom".
Ahead of the match, FIFA's Human Rights department sent an email to fans who complained about treatment at earlier Iran matches, clarifying that 'Women.Life.Freedom' or the name or portrait of Mahsa Amini - the woman whose death in Iranian police custody sparked the unrest - are allowed in stadiums.
Reuters saw the text of the email.
Qatar's World Cup organisers said that "security authorities stepped in to deescalate tension and restore calm." Qatar's government media office did not respond to a request for comment.
"A Real Problem"
While fans see a double standard, analysts say the approach reflects the political priorities of Qatar, a conservative Muslim country with an authoritarian government that has long walked a diplomatic tightrope.
Its policies have included building good ties with Iran while hosting the region's largest U.S. military base, and hosting the Palestinian Islamist group Hamas while previously having some trade relations with Israel and allowing Israelis to fly direct to Doha for the World Cup - a first.
For fans, inconsistent enforcement of rules had been "a real problem", said Ronan Evain, executive director of Football Supporters of Europe. "What we see in the end is that FIFA has lost control of its own tournament."
He said there had been "staggering" inconsistency over Iranian slogans, saying fans had worn T-shirts declaring support for the protests at some games while getting into trouble for wearing them at Iran's matches.
He saw similar inconsistency when it came to shows of support for LGBT+ rights, for which Qatar has faced heavy criticism because of its ban on homosexuality.
While rainbow flags are in theory allowed, "in practice we see that this is very different", he said. "This inconsistency...is putting fans at risk," he said.
A FIFA Qatar World Cup stadium code of conduct prohibits banners, flags, fliers, apparel and other paraphernalia of a "political, offensive and/or discriminatory nature".
A FIFA spokesperson said it was "aware of some incidents where permitted items were not allowed to be displayed at stadiums", and continued to work closely with Qatar to ensure full implementation of regulations.
Iranian-American Saeed Kamalinia said he wore a T-shirt declaring "Women Life Freedom" to six games but concealed it on his way through security for two of Iran's matches and decided against wearing it to the United States game, fearing a crackdown.
By contrast, symbols of support for the Palestinians have been widely seen. "I felt welcomed by the Qatari people and by all present here ... people greet us with ‘Palestine Palestine'," said Palestinian fan Saeed Khalil.
Maryam Alhajri, a Qatari member of Qatar Youth Against Normalization, a vocal group opposed to Arab normalisation with Israel, said pro-Palestinian sympathies showed "that Palestine remains the primary Arab cause".
Arab states including the United Arab Emirates and Morocco - cheered by many Arab fans for making it to the last 16 - normalized ties with Israel in 2020.
For Qatar, allowing shows of support for the Palestinians was part of a "hedging strategy", said Mehran Kamrava, a professor of government at Georgetown University Qatar.
Qatar was "allowing the population to vent their anger and demonstrate their support symbolically for Palestine, while at the same time the government is laying the groundwork for improving relations if not fully normalizing them".