Cast your minds back to 1975, when the Internal Revenue Service created a furor by proposing regulations that would treat many fringe benefits as income for tax purposes.

Members of Congress, Sen. Daniel Patrick Moynihan (D-N.Y.) explained to his colleagues the other day, "were deluged with mail from airline employes who were upset about possibly having to pay taxes on their discounts on airline tickets and from college professors who did not want to be taxed on tuition remissions that colleges offer children of university faculty."

So Congress, recognizing a clear and present danger, imposed a moratorium on fringe benefit regulations and has since extended that moratorium twice.

The current version will expire at the end of 1983. In the meantime, industrious IRS agents have decided to go after another similar-sounding benefit.

It seems that four colleges in New England -- Amherst, Smith, Wellesley and Wesleyan -- own apartments and residences that they rent to faculty members at cost. The difference between what faculty members are charged and what the colleges could charge on the open market should be taxed, according to an IRS technical advice memorandum.

What's at issue in cases like this, an IRS official said, is the question of whether the lodging is provided for the convenience of the employer. If it is, then it is not taxable. If, however, it is provided for the convenience of the employe, then it is taxable.

These New England colleges, by no means the only ones with such arrangements, contend the practice is critical to building close relationships between students and teachers, since it keeps faculty near campus and puts affordable housing within their reach.

Moynihan and Sen. John Heinz (R-Pa.) have introduced legislation that would place those arrangements under the fringe benefit moratorium.