The fact-checking movement is all grown up.

With Factcheck.org turning 13 this year, fact-checking is now a staple of American political coverage. And although they took hold later, by and large, international fact-checking initiatives are not exactly new either: Désintox launched on France's Libération in 2008; Argentina’s Chequeado and the UK's Full Fact are both six years old.

With this in mind — and even as they candidly shared stories of failure — participants of the Third Global Fact-Checking Summit agreed to take steps to strengthen the reliability of fact-checking as a tool of accountability journalism while also finding ways to expand its reach.

A key discussion involved a shared code of principles that would push fact-checkers towards ever-greater transparency and consolidate readers’ trust in the instrument.

The code will emphasize a commitment to nonpartisanship as well as to transparency in methodology, sources and funding.

"Most fact-checking organizations already abide by these principles, but having a written code we can all sign up to will have clear advantages," says Peter Cunliffe Jones, director of Africa Check.

For one, a set of principles could help distinguish good fact-checking from bad, at a time when political campaigns, authoritarian governments and lobbying groups with dubious agendas try to claim the term.

"We will seek advice from fact-checkers all around the world in the coming weeks," says Cunliffe-Jones.

Phoebe Arnold, senior communications officer at Full Fact, notes that "fact-checkers are a diverse group of organizations working in very different political environments," which could make it challenging to create a code that is globally applicable.

However "this diversity of experience" has its advantages, Arnold says, namely "being able to draw on the very best practices from around the world."

A parallel working group in Buenos Aires considered the establishment of an informal International Fact-Checking Day. This could help rally educational initiatives aimed at building critical thinking in school and encourage development and use of fact-checking tools.

While the timing and format are yet to be determined, dates floated for this day included April 2, which would consecrate the event as the mirror-opposite of April Fool’s Day. Fact-checkers half-jokingly considered reaching out to Google and Twitter, to develop tailored doodles and twitter emojis — or even the UN. After all, if yoga has a dedicated international day, shouldn’t fact-checking?

Pablo Fernàndez, editorial innovation coordinator at Chequeado, noted that the day "could help us increase the impact of all fact-checking organizations, as their digital and physical content could reach new audiences that usually don't know about us. We need it."

Amy Hollyfield, deputy managing Editor at The Tampa Bay Times suggests it could be "a day for action, with united efforts fact-checking a topic critically important across the world."

Other concrete projects to emerge from Global Fact 3 include the rollout of the “Share the Facts” widget to international fact-checkers, a working group on joint impact-tracking and the establishment of a fellowship to enable fact-checkers to spend one week embedded with other fact-checking organizations around the world.