A recent rule change is to allow coaching on court on a limited basis during a match.

Until now, the drug agency has allowed their use in dairy herds only on an experimental basis.

Since 2007, the survey has moved to a continuous design, allowing the provision of headline findings on a quarterly basis.

Hers would allow them on a case-by-case basis in most areas, provided they met specific performance standards.

To allow hiring of principals on a contractual basis for, say, five years might be a sensible legislative change.

Other categories, like different versions of the same game, are allowed on a game-by-game basis.

For anyone else, there was the need to allow the person time as himself, in human form, on a regular basis.

As a result, this allows a certain degree of flexibility on a case-by-case basis.

None of these would allow immigration, except on a reciprocal basis, which made the project impractical.

That is because 401(k) plans are increasingly allowing such trading, often on a daily basis.