And under its "parallel track" policy, it makes some promising new drugs available to people with H.I.V. who do not meet the eligibility rules for clinical trials.

Since the 1980's, a variety of mechanisms have made entry into the shelter system harder and discharge easier, but requiring those seeking shelter to meet the same eligibility rules as welfare recipients would dwarf past changes, providers said.

Typically, any high school that meets the eligibility rules of the National Science Bowl competition is permitted to register for any regional competition in the country, but no high school or student group may compete in multiple regionals.

They must meet the same eligibility rules as the students enrolled in the district's schools.