HARRISBURG - As she crisscrossed the state during the summer to train public officials in the nuances of the state's new open-records law, Terry Mutchler's message boiled down to a single, defining guideline.

"I told people: You can use this law as a way to block and shield information, or you can use it to help citizens get more access," said Mutchler, the head of the state's new Office of Open Records.

With the law going into effect today, Mutchler said this week, "I believe we're going to see a little bit of both."

The legislation will free Pennsylvania from having one of the worst records in the nation - some believe it was the worst - in providing access to government documents.

In essence, it declares that all state, county and local government records are public unless specifically exempted. It is a vast change from the state's previous Right to Know Act, written in 1957, which had a very narrow definition of what constituted a public record.

The law also shifts the burden onto a government agency to prove why a record should be shielded from the public. Previously, the burden was on citizens. Mutchler's office will decide any disputes that arise.

And for the first time, the legislature will be subject to the law.

The law is retroactive and covers records already collected by government agencies - a major win for open-records advocates.

"Overall, we're pretty pleased with it," Barry Kauffman, the Pennsylvania executive director of Common Cause, said of the new law. "The key is that now, all records are open unless they fall under specific exemptions - and it's up to the government to prove why they should be closed. Those two changes alone are culture-changing in Pennsylvania."

Still, Kauffman and others stress that the law is far from perfect, and is weaker than laws in some other states. And they believe there will be some initial growing pains as state and local government agencies begin to implement it.

In the new law, there is a series of exceptions for material that in other states is part of the public record.

Take 911 tapes. Under the new law, the tapes, in most circumstances, will be closed in Pennsylvania. The law states that those tapes (or transcripts) are exempt from disclosure unless an agency or a court determines that the public interest in making them public outweighs the interest in keeping them private.

Other states routinely allow access to 911 transcripts or tapes, among them Arizona, California, New York, Ohio and Texas.

Another exemption in Pennsylvania's law: autopsy reports (with the exception of the deceased's name, and cause and manner of death).

Many states generally permit access to such reports or portions of the reports, including Colorado, Kansas and Louisiana.

"While I don't think it's a perfect law, before this Pennsylvania without question had the worst open-government-records law in the country," said Lucy Dalglish, executive director of the Reporters Committee for Freedom of the Press, a nonprofit that tracks open-records laws around the country.

"The new law will hopefully put Pennsylvania squarely in the middle," she added.

But there is also the matter of implementing it.

Some public officials fear they will be deluged by records requests - some reasonable, others not - in the next few months, while the law is still new.

And some advocates say there still is a handful of public officials who are resistant to the philosophy of the new law: that all government records are public unless specifically exempted.

Case in point: Hamilton Township, Adams County. At a town meeting this week, one of the supervisors refused to disclose salaries or cost of benefits for any township employees, according to the Hanover Evening Sun.

That information is not just available under Pennsylvania's new law, however; it was public under the old one as well.

The supervisor could not be reached for comment. But Mutchler's office has sent him a letter this week informing him of the law's requirements.

Generally, if a government agency has been found to have withheld records in bad faith, a court can impose a civil penalty of up to $1,500. And an agency or public official who does not comply with a court order to release documents can be fined $500 a day until the records are released.

Still, Douglas Hill, executive director of the County Commissioners Association of Pennsylvania, believes the law is explicit enough to prevent abuse from either government agencies or citizens.

"I think the new law helps both sides," said Hill. "People have a better sense of what they are entitled to receive, and [government agencies] have a better sense of what they are required to turn over."

Mutchler put it this way: "The reality is, this is not rocket science. Are there going to be questions about the law, and is there going to be litigation? Yes . . . but in most cases, it's basic black-letter law."

She added: "I want everyone to take a deep breath. The world is not going to end with the release of new records in Pennsylvania."