Fannie Mae, Freddie Mac and the Federal Home Loan Banks will now be prohibited from taking on mortgages “encumbered by certain types of transfer fee covenants and in certain related securities” under a final rule issued last week by the Federal Housing Finance Agency. The FHFA’s final rule, published in the March 16 Federal Register, generally applies, with some exceptions, to private transfer fee covenants created on or after Feb. 8, 2011, the publication date of the Finance Agency’s proposed rule.