Here are four words that should be memorized and occassionally mobilized by all of those in the public eye who are likely to be interviewed on television: "None Of Your Business." How sweet life would be if just one person would have the guts to say that to that pandering, taltentless, definitively vacuous environmental hazard, Rona Barrett.

"When did you make your mother cry?" she asks her hapless guests on tonight's deplorable ABC special "Rona Barrett Presents: That's My Mom," at 8 on Channel 7. "Were you raised to be affectionate?" she blankly inquires.

Rona, honey -- none of your darn business! Take a hike! Grab your lavalier mike, your nuclear hairspray, your parody of curiosity and your cue cards and get the heck out of my house! It's what they all should have said -- Kristy McNichol, Bo Derek, Kenny Rogers, Larry Hagman and their mothers. But they didn't.

Poor Miss Rona. She thinks she's a journalist. Recently she did an embarrassing public pout on the Tom Snydor "Tomorrow" show about how badly ABC has treated her and how she really invented the format for the Barbara Walters specials. Of course she is no less a sad joke as an interviewer than she is as a movie "critic" on ABC's "Good Morning, America."

Producer-director Lawrence Einhorn, however, gave her assistance fit for a queen with this special. The researchers in particular dug up some splendid old movie and TV clips about how mommies have been portrayed in public -- everything from Ma Joad in "The Grapes of Wrath" to Nixon's "ymy mother was a saint" to Joan Crawford telling her daughter "Get out, get out before I kill you" in "Mildred Pierce" to Joson "Mammy" to the now-extinct TV toothpaste commercial, "Look Ma, no cavities!"

In fact, there is nothing about the Rona Barrett special that's totally unacceptable except for Rona Barrett.

By now, most stars have learned how to speak People Magazinese, so even if there were any reason to be interested in how they regard their mothers, the insights offered are shamefully sham. The one provocative relationship appears to be between Larry Hagman and his mother, Mary Martin. They don't exactly gush over one another.

But Hagman, who also fields an interpolated question about the J.R. Ewing he plays on "Dallas," does have the right attitude about being interviewed by a human dandelion. "Do you remember how you used to get your mother's attention?" Barrett asks him. "Yes," Hagman replies. "I used to say. 'Mother, would you pay attention to me?' And she would say, 'Yes, I will.'"

That and the film clips are slim reward, through, for enduring this subcamp romp. The hour amounts to a vacant lot presided over by a Blondie for the '80s. Miss Rona has the journalistic credentials of Donny and Marie, the sparkling personality of Hodding Carter and the beside manner of Madame LaFarge.