The "Steinmeier Formula" is little spoken about yet it has been touted by some as a possible route to armistice in eastern Ukraine, where pro-Russian separatists have fought with Ukrainian forces.
It is a peace plan of sorts, proposed by German President Frank-Walter Steinmeier back in 2016 when he was foreign minister. But what does it consist of and where do Russia and Ukraine stand on its implementation?
What exactly is the 'Steinmeier Formula'?
The conflict in eastern Ukraine has left around 13,000 people dead, a quarter of them civilians, according to the UN, and wounded up to 30,000.
In September 2014 — and again in February 2015 — Ukraine and Russia, along with France and Germany, signed off on the so-called Minsk agreement, a plan to establish peace.
Painting the two key actions the agreement encompasses with a broad brush, they amount to holding local elections and returning pro-Russian separatist regions to Ukraine's control.
However, there was no clear indication of the order in which steps should be taken.
The "Steinmeier Formula" is a sequencing of the agreement, Peter Dickinson, publisher of Business Ukraine magazine and fellow at the Atlantic Council told Euronews.
What is Russia's position?
"In it's most Moscow-friendly interpretation, the formula holds elections would take place (in eastern Ukraine) with the current security environment still in place," Dickinson said. "Essentially with the separatist/Russian forces still in charge."
This could legitimise Russian proxies or appointees by seeing them elected, he added.
Moscow would like to see the status quo confirmed in this way, to ensure it has influence in the area to stop Western integration and it could then stage a "theatrical retreat", Dickinson explained.
How do Ukrainians feel about the formula?
"Ukraine seems to be hedging its bets somewhat," Dickinson said.
While foreign minister Vadym Prystaiko said on Wednesday Kyiv had "already agreed" to the "Steinmeier Formula", the country also held a working group this week which laid out conditions surrounding the roadmap and refused to sign a "blank cheque".
When it was first voiced in 2015, the Steinmeier Formula was rejected, so there is a feeling that accepting it now would be a concession, he explained.
There is a lot of uncertainty among the public about what the government has agreed to and it will have to be careful not to appear to offer too many concessions.
"Any attempt to legitimise the Russian forces in eastern Ukraine and local representatives appointed by the Russians would be a red line in Ukrainian public opinion," he said.
But the country is "war-weary" and new President Volodymyr Zelensky has huge momentum, enjoying unprecedented popularity, and wants to deliver peace.
There is also the fear, however, that Zelensky is an unknown quantity and political novice who is going up against Putin, Dickinson added.
The meeting to firm up the formula between the Normandy Four — leaders of France, Germany, Ukraine and Russia — was set to take place on September 17.
But it didn't go ahead.
Tasked with finding a solution to the conflict, their last meeting was in 2016.
There is talk of the meeting being pushed to the end of September or early October, according to Dickinson.
Russia has said it will not attend a summit unless they have guarantees of progress — essentially they want an agreement to be ready to sign, he added.
While there is a fear in Ukraine that the three other actors will force the country's hand to resolve the conflict, it is "tired" of war, said Dickinson.
It remains to be seen how far Zelensky is willing to go in compromising to remedy the situation in the East.