The phrase "a point of warning" is correct and usable in written English.
It can be used when you want to highlight a caution or alert someone about a potential issue or risk.
Example: "Before we proceed with the project, I want to make a point of warning about the budget constraints we may face."
Alternatives: "a word of caution" or "a note of warning".
In 1984, Walter F. Mondale made a point of warning voters that he would raise their taxes.
Rafael Benítez had made a point of warning his players against complacency in the buildup to this contest but, clearly, that message did not entirely sink in.
This is the manager who made a point of warning the waitresses at the hotel in Wrightington, where they were staying before the corresponding fixture at Bolton last October, not to "sell any chocolate to my players".
Mr. Bloomberg, who has said that his tenure should be judged by how much the schools improve, has recently made a point of warning how difficult and slow any change will be.
In his first interview after Mr Mandelson's resignation, Mr Blair made a point of warning potential revisionists that New Labour was bigger than any individual, and would resist any return to old policies.The Tories would love Labour to reopen these battles.
He stressed that "we make a point of warning promoters that we are not a dancing group".
No doubt there will also be those who, hiding behind their nervous and cautious reticence, will push their shamelessness to the point of warning others against a text that can only "irritate the American judge even more".
Trump has for months contended that the U.S. economy is in trouble because of what he sees as an overvalued stock market, but his view has grown more pessimistic of late and he is now bearish on investing, to the point of warning Americans against doing so.
They point to a host of warning signs: high deficits, intractable unemployment, stunted economic growth, diplomatic setbacks.
In earlier interviews with me, senior F.B.I. counterterrorism officials had made a point of criticizing such vague warnings.
"Mom was being very vocal with the calf," she said of Kasatka, not as any kind of warning, just a point of information.
