The Supreme Court indicated yesterday that laws banning all billboards night be permissible under the Constitution.

But the court's opinions were so many and so varied -- a "Tower of Babel," as one justice put it -- that they offered little guidance to states, counties and cities trying to protect the environment with billboard restrictions.

Several cities and three states -- Maine, Vermont and Hawaii -- have almost totally banned billboards. Others have more limited regulations.

The justices were considering a San Diego ordinance that banned most signs but made exceptions. For example, a business could erect a sign on its premises. No such special treatment was given to political billboards or billboards expressing non-commercial viewpoints.

That was the main reason the San Diego ordinance was struck down yesterday. Four justices, led by Byron R. White, said the exceptions to the ban, not necessarily the ban itself, made it unconstitutional.

There were two separate opinions, one by the four justices and one by two others, voting to invalidate the ordinance. There were three separate dissents.

Amid the many voices was at least one general point of agreement, pieced together independently of how each felt about the specific San Diego case.

Five agreed on the constitutionality of a ban on all billboards. Justices William J. Brennan Jr. and Harry A. Blackmun, who voted to strike down the San Diego law, said "a city may totally ban them if it can show" a solid reason. In separate dissents, John Paul Stevens, William H. Renquist and Chief Justice Warren E. Burger agreed that a total ban was permissible.

That made a court majority. But the force of what they said was limited by the way they said it and their disagreement on the reasons and the actual judgement overturning the law.

White and his three supporters, Potter Stewart, Thurgood Marshall and Lewis F. Powell Jr., said they chose not to address the constitutionality of total bans. They said a ban on commercial billboards alone was permissible. But no billboard law could, like San Diego's, actually treat political and ideological messages worse than commercial pitches, they said.

Beyond that, the legality of the various combinations of restrictions employed by most governments remained unclear. The court may address the issue in coming years.

The ruling was an extreme example of a problem that has plagued the Burger court in many important cases. The Bakke decision on affirmative action in 1979 was similarly clouded by multiple views.

Rehnquist took the court to task for its handling of the San Diego case. "In a case where city planning commissions and zoning boards must regularly confront constitutional claims of this sort, it is a genuine misfortune to have the court's treatment of the subject be a virtual Tower of Babel, from which no definitive principles can be clearly drawn," he said.

The court seemed to have been perplexed by its own complicated distinctions in the area of free speech. Political views have received the highest level of protection from the court, but various and ill-defined "compelling" reasons may allow various limitations.

Commercial speech -- advertisements -- has been protected but less so than non-commercial speech.

Yesterday, the two lines of decisions came together in one case. The result, one industry lawyer said, "will take us a year to figure out."