Russian athletes must prove they are clean before they can return to international competition, athletics' governing body has warned.
Russians are banned from competing by the IAAF because of widespread state-sponsored doping in their country.
Now it has issued guidelines to Russian athletes, spelling out what they need to do before they can compete again.
A recent report said more than 1,000 Russians, including Olympic medallists, benefited from a doping programme.
"Russian athletes have been let down by a system that should have protected them," said Lord Coe, chairman of the International Association of Athletics Federations.
The IAAF banned Russian athletes from competition in 2015 in response to allegations of state-sponsored doping. Before last summer's Olympic Games in Rio, the governing body outlined "strict criteria" any Russian athletes must meet if they wanted to take part in the Games.
Only one athlete was able to meet the criteria - US-based long-jumper Darya Klishina, who entered as a neutral.
Those guidelines have now been updated and sent to Russia's athletics federation. They say Russian athletes wanting to compete need to prove they have never been implicated "by their national federation's failure to put in place adequate systems to protect and promote clean athletes".
It also points out any athletes cleared to compete will only be allowed to take part under a neutral flag.
The updated criteria also asks Russian athletes to show:
* Whether any coach, doctor or other support person with whom they have worked has ever been implicated in the commission of any anti-doping rule violations;
* The number of urine, blood or athlete biological passport (ABP) samples they have had collected;
* Whether they were subject to testing by the IAAF or any other national or international World Anti-Doping Agency (Wada) recognised testing authority;
* Any atypical findings or concerns about their ABP profile, requiring further investigation after a drug testing sample has been provided;
* Whether any samples previously provided by them are currently in storage or need retesting.
The IAAF said applications would be reviewed by its Doping Review Board (DRB), who will decide whether applicants will be granted neutral athlete status.
Last month, the IAAF decided to extend Russia's ban - which was first announced in November 2015 - meaning the country will miss March's European Indoors in Belgrade, Serbia.
Since then the second part of a report for Wada by lawyer Richard McLaren has been published, stating that more than 1,000 Russians across 30 sports benefited from a state-sponsored doping programme between 2011 and 2015.