The social network said the policy was introduced to reduce the amount of cyber-bullying on its platform, but added that it now recognised the approach had been flawed.
The measure was exposed by the German digital rights news site Netzpolitik.
Disability rights campaigners said the strategy had been "bizarre".
A leaked extract from TikTok's rulebook gave examples of what its moderators were instructed to be on the lookout for:
Such users were "susceptible to bullying or harassment based on their physical or mental condition", the guidelines added.
According to an unnamed TikTok source quoted by Netzpolitik, the moderators were told to limit viewership of affected users' videos to the country where they were uploaded.
And in cases where the creators were judged to be particularly vulnerable, it reported that the moderators were ordered to prevent the clips from appearing in the app's main video feed once they had reached between 6,000 to 10,000 views.
This video feed is auto-generated and personalised for each member. It accounts for where most people spend their time watching others' content.
Netzpolitik reporter Chris Koever suggested the result was that the Chinese-owned firm had further victimised those affected "instead of policing the perpetrators".
A spokesman for TikTok admitted it had made the wrong choice.
"Early on, in response to an increase in bullying on the app, we implemented a blunt and temporary policy," he told the BBC.
"This was never designed to be a long-term solution, and while the intention was good, it became clear that the approach was wrong.
"We have long since removed the policy in favour of more nuanced anti-bullying policies."
TikTok has not confirmed when it abandoned the measure, but Netzpolitik reported that it was still in force in September.
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