One possible alternative to the pressure test would involve tightening restrictions on tailpipe emissions.

Both sets of pressures involve restrictions of one sort or another.

Another dramatic shift at United involves restrictions on which flights passengers can choose when they turn in their mileage credits for tickets.

As a result, they have adopted special economic policies, typically involving low levels of taxation and few restrictions on external financial investment.

The case, involving restrictions on donations in Missouri state races, also demonstrated the philosophical anguish at the court over the issue.

Incest laws may involve restrictions on marriage rights, which also vary between jurisdictions.

Natural-resource-management courses tend to involve restrictions on use of land and water to prevent ecological damage.

While most of the clashes across the country have involved proposed restrictions on illegal immigrants, some states have voted to expand access for them.

Other activities, such as mergers and financial report preparation generally involve similar restrictions.

They found the problem involved dietary restrictions imposed by well-meaning parents who were worried about obesity.