20 USC 7906 - General prohibitions

(a) Prohibition 
None of the funds authorized under this chapter shall be used
(1) to develop or distribute materials, or operate programs or courses of instruction directed at youth, that are designed to promote or encourage sexual activity, whether homosexual or heterosexual;
(2) to distribute or to aid in the distribution by any organization of legally obscene materials to minors on school grounds;
(3) to provide sex education or HIV-prevention education in schools unless that instruction is age appropriate and includes the health benefits of abstinence; or
(4) to operate a program of contraceptive distribution in schools.
(b) Local control 
Nothing in this section shall be construed to
(1) authorize an officer or employee of the Federal Government to mandate, direct, review, or control a State, local educational agency, or schools instructional content, curriculum, and related activities;
(2) limit the application of the General Education Provisions Act [20 U.S.C. 1221 et seq.];
(3) require the distribution of scientifically or medically false or inaccurate materials or to prohibit the distribution of scientifically or medically true or accurate materials; or
(4) create any legally enforceable right.