GROTON — About 40 people learned about the state’s Open Meeting Law, and the revisions to it going into effect next July, during a recent seminar at Town Hall.

Many in attendance are Groton board members looking for guidance as to the posting of meeting notices, requirements for meeting minutes, usage of e-mail and procedures for executive sessions.

Kerry Kilcoyne, the Middlesex assistant district attorney who coordinates that office’s Open Meeting Law team, led the seminar. She walked the audience through the current law and the guidelines for towns’ compliance.

The law dictates that the public has rights to at least 48-hour notice in advance of meetings, unimpaired access to meetings and meeting records, and the right to videotape or audiotape meetings unless it’s an executive session, which is closed to the public.

Citizens, however, have no right to speak at a meeting, except as allowed by the chairperson.

Kilcoyne previewed key changes to the law as passed in July, covering not just open meetings but campaign finance, ethics and lobbying. A major change will be that the state attorney general, not district attorneys, will have authority over the law.

The attorney general will administer a new body, the Open Meeting Law Advisory Commission, which will review enforcement of the law and any complaints.

Kilcoyne said the commission will include a representative of the newspaper industry, traditionally a watchdog on open meetings and executive sessions, when meetings are closed to the public for sensitive legal reasons.

Among the changes she highlighted were that the 48-hour notice will no longer include Saturdays, Sundays or holidays.

Another is that the posting for a meeting will need to include an agenda and must be displayed in an area that is visible around the clock at a town or city hall, possibly requiring an outdoor bulletin board.

Also, the law says meeting minutes will have to be more detailed concerning discussions, documents and exhibits. Currently, the law allows more general summation.

The attorney general will have broader enforcement powers, including civil penalties for violations. The law will put the onus on a town to go to court if it disagrees with the attorney general’s ruling on a violation.

Groton Town Clerk Michael Bouchard hosted the seminar. He called it a training opportunity provided for towns. He said it had nothing to do with a controversy in Groton earlier this summer when a selectman charged that the town’s Zoning Board of Appeals had been in violation of the Open Meeting Law in its administration of affordable-housing projects.