The phrase "collective warning" is correct and can be used in written English.
It refers to a warning given to a group of people or a community rather than an individual. Example: The village elders issued a collective warning to the young generation about the dangers of neglecting their traditional values.
"We must stand together, we have collective responsibility," he said, warning of a risk of new nationalism in Europe.
Without warning, a collective of alien races known as the Covenant began attacking the outlying colonies, brutally exterminating all life by vitrifying the surface of the planets.
The DIY Guide to Feminist Cybersecurity by Safe Hub Collective opens with a warning: "it's a jungle out there and you need to take the initiative to protect your digital space".
Despite international criticism and warnings of "collective punishment", Israel's supreme court in January approved a government policy to cut fuel supply to Gaza.
In a striking defection among the Socialists, Louka Katseli, a party stalwart and former labor minister, voted against a controversial element in the bill on collective bargaining, defying government warnings that rejection of any provisions of the legislation could jeopardize the release of rescue financing on which the country's solvency depends.
Is this collective seasonal nostalgia, or a warning that we should swaddle ourselves in scarves, long johns and thermal underwear?
But in the process we've lost entirely the romance of neurosis, as well as its physical embodiment — a restless, grumbling, needy presence that once functioned in the collective mind as an early warning system, an inner voice that hedged against excessive optimism.
Without warning, an alien collective known as the Covenant attacks the outer human colony of Harvest.
But Palestinian civilians in Gaza say they are being indiscriminately shelled by Israel as a form of collective punishment, often with inadequate warning and nowhere safe to go.
Sanders, meanwhile, made it clear that he has had enough with a lot of things, including and especially the tyranny of the Wall Street casino game and our collective refusal to address global warning.
