Chalk dust and powder substances have been banned from Wimbledon this year, organisers said.
The All England Lawn Tennis Club (AELTC) said these are new banned items which were not listed in 2022.
It comes as security arrangements at the tournament were boosted in the wake of a series of environmental protests at other large sporting events.
Climate change group Just Stop Oil (JSO) disrupted the second Ashes test at Lord’s, the Gallagher Premiership rugby final at Twickenham and the World Snooker Championship.
A JSO protester was carried off the pitch at Lord’s by England’s Jonny Bairstow as activists threw orange paint dust during play in June.
The group disrupted the Gallagher Premiership rugby final at Twickenham by invading the pitch and throwing orange powder paint in May.
A match at the World Snooker Championship was interrupted in April when a man wearing a Just Stop Oil T-shirt jumped onto a table and tipped orange powder over the cloth.
Cable ties, glue, chains and padlocks are also listed as banned items.
The Wimbledon website makes it clear that visitors with any banned item “may be refused entry or ejected from the grounds” and any items surrendered as a condition of entry cannot be reclaimed.
