The Federal Housing Finance Agency last week issued its final rule on the uniform MBS, the single security that Fannie Mae and Freddie Mac will package and sell. Its success, though, may depend on the much-contested definition of the rule: What are “covered programs, policies or practices”?

The Federal Housing Finance Agency late this week issued a final rule aimed at improving liquidity of the to-be-announced MBS as well as the new uniform MBS, which makes its debut in early June.

The Securities Industry and Financial Markets Association and the Investment Company Institute, in a joint letter, urged the Internal Revenue Service and the Treasury Department to clarify certain diversification requirements under the single security initiative.

Late last month, the Securities Industry and Financial Markets Association held a meeting that could impact the future of the Federal Housing Finance Agency’s single security initiative.