Yale has told security officer John W. Powell to destroy his files on "subversive" Yale students. The ex-FBI man was also directed to cease investigations into the political activities of faculty and students.

The university's action followed a two-week campaign by the Yale Daily News against the "misapplication of FBI techniques to the campus police force." Powell had kept files on students under such labels as "Subversive Activities, Organizations, and Individuals."

In a five-point memorandum to Powell, Yale Provost Kingman Brewster, Jr. outlined what the limits and prerogatives of the campus police were to be.

Powell was also asked to be aware of non-University groups "which seek to use Yale facilities for unauthorized purposes, including political purposes." But he was warned against keeping records of students affiliated with these groups.

Brewster's memorandum also forbade Powell to make his files on students available to potential employers. Information on students at Yale will be channeled only through the deans and college masters.