World cricket chiefs have approved a ban on using saliva to polish the ball and backed the introduction of coronavirus substitutes.
The International Cricket Council (ICC) gave its approval amid a raft of interim changes to regulations in the wake of the COVID-19 pandemic hitting sport.
Rules on kit sponsorship have also been relaxed for 12 months, allowing teams to bring in extra revenue through placing a logo on the chest of their Test shirt and sweater.
There has been no international cricket since March due to the health crisis and the global governing body is keen to mitigate risks posed by the virus, protecting the safety of players and match officials.
Bowlers traditionally apply saliva to the ball to make it swing, but they will have to rely on sweat when the sport returns, with the use of any artificial substance already outlawed.
The saliva ban was passed despite a number of players, including former Australia captain Steve Smith, suggesting it would give batsmen an advantage.
Repeatedly breaching the new rule could result in teams receiving a five-run penalty.
An ICC statement read: "Players will not be permitted to use saliva to shine the ball. If a player does apply saliva to the ball, the umpires will manage the situation with some leniency during an initial period of adjustment for the players, but subsequent instances will result in the team receiving a warning.
"A team can be issued up to two warnings per innings but repeated use of saliva on the ball will result in a five-run penalty to the batting side.
"Whenever saliva is applied to the ball, the umpires will be instructed to clean the ball before play recommences."
Among the other changes will be the introduction of coronavirus replacements for Tests, but not Twenty20 internationals or ODIs.
If a player displays symptoms of COVID-19 during a Test series, teams will be allowed to replace them with "the nearest like-for-like replacement".
The ICC has also removed the requirement for a neutral umpire in all formats, due to restrictions on international travel.
With this perhaps leading to the use of officials with less international experience, an additional unsuccessful DRS review will be granted.
"This will increase the number of unsuccessful appeals per innings for each team to three for Tests and two for the white-ball formats," said the ICC.
"The ICC cricket operations team will support match referees when processing code of conduct breaches, and a neutral elite panel match referee will conduct any hearing remotely via video link."