(FORTUNE Magazine) – Quick -- what do the following business enterprises have in common: Boise Cascade, Sundstrand, the Winery Employees Association (of San Francisco), and Hormel? Answer: They are among the numerous employers who have invoked the Mackay Doctrine in 1986. And what is the Mackay Doctrine? (That will be the last rhetorical question for, oh, two or three paragraphs.) It is a statement of the employer's guiding philosophy with respect to his human resources, and can be briefly summarized as: ''Look, Charlie, if you don't like it around here, please feel free to get lost.'' To be sure, that is not the way sobersided James A. Prozzi capsulized it in his article in the National Law Journal last May. Prozzi, a Pittsburgh specialist in labor law, mentions several different propositions that collectively make up the doctrine. One is that employees have an undoubted right to strike over economic issues. Another is that struck employers have an equally undoubted right to continue operating by hiring replacements for the striking workers. Finally, the Mackay Doctrine -- which happens to be the law of the land -- nonchalantly adds that the companies may keep these replacements on the job, and elect not to take back the characters who walked out, even when they smilingly announce that they are again available. This last feature of the Mackay Doctrine is putting a new light on the right to strike. In a CBS News feature a few weeks back, correspondent Jane Bryant Quinn sorrowfully noted that the U.S. today seems to be full of workers willing to cross a picket line. In the circumstance, she concluded: ''The right to strike is becoming nothing more than the right to quit.'' By George, she's got it. The Mackay Doctrine has some peculiar antecedents. It is actually part of the Wagner Act of 1935. Or, at least, that is what the Supreme Court decided in 1938, after Mackay Radio & Telegraph had refused to rehire four strikers. There is evidence that Senator Robert F. Wagner was not too wild about this interpretation by the Court; however, it has held up for half a century, and Prozzi doubts that Congress is in a mood to reverse it now. The AFL-CIO does not expect an early reversal, as evidenced by the fact that its 1985 convention called only for educating the public to how unfair the law was. What the porkchoppers would really like, one intuits, is Canadian logic. Our neighbor to the north has this law giving economic strikers a right to return to their jobs within six months after the strike ends, even if their return means zapping the replacements. But why is Mackay suddenly in the news today, after being on the books for 48 years? How can it be that employers had the right all these years to, in effect, fire strikers, but always acted as though this would be considered too impolite to countenance? Possible answers: Some employers were emboldened by Reagan's dismissal and replacement of the striking air-traffic controllers in 1981. Some just became desperate when deregulation and foreign competition made them unable to pass along the costs of unionism to the consumers. Some doubtless observed that the endless sag in the American labor movement was making the opposition to permanent replacement much less formidable. (See Managing for more on the sag.) Somewhere out there you might even find a human resources manager influenced by pro-scab sermonettes in Keeping Up. A funny thing about the U.S. Labor Department, which can instantly spit out an unemployment rate for Vietnam-era veterans aged 35 to 39, is that it collects no data on the incidence of Mackayism among employers. Nobody knows exactly how many companies have gone for one or another form of a permanent + replacement strategy in 1986. But, as usual, Nexis serves up lots of examples. In addition to those mentioned above, Swift Independent Packing, TWA, Weyerhaeuser, Colt Industries, AT&T, the Tribune Company, and BASF have given their workers a right to quit.