Twitter could add bright orange and red labels to tweets that include lies and misinformation.
The plan is just one of a range of plans being considered by Twitter to cut down on the spread of false stories, according to a leak.
A design mock-up obtained by NBC News shows how verified fact-checkers and journalists can highlight incorrect tweets directly below the original post.
There also appears to be a way for others to add their feedback, with a Participate button.
Misinformation was under the spotlight during the 2019 general election and continues to be a concern as the US prepares for the presidential election later this year.
Offending material is described as harmfully misleading in a tab underneath, which reads: "Twitter community reports have identified this tweet as violating the community policy on harmfully misleading information.
"This tweet's visibility will be reduced."
The mock-up examples include a tweet by US presidential hopeful Senator Bernie Sanders about gun background checks and another by House Minority Leader Kevin McCarthy regarding whistleblowers.
Twitter confirmed it is currently in the very early stages of considering the feature, so early that the project is not even staffed yet, the tech giant claims.
"We're exploring a number of ways to address misinformation and provide more context for tweets on Twitter," a spokeswoman said.
"This is a design mock-up for one option that would involve community feedback.
"Misinformation is a critical issue and we will be testing many different ways to address it."
Additional reporting by agencies
