And honey-dipped apples are allowed for Jewish New Year, but programs that use the Koran and bible are banned from class time.

The Andrews government has released detailed new guidelines for special religious instruction in state schools, after announcing in August that it would scrap the controversial program from the curriculum.

Under the new rules, which come into effect in January, the 30-minute classes must be delivered during lunchtime, or before or after school.

A ministerial directive says principals must ensure SRI providers do not entice students with treats and rewards. Teachers still have to supervise the classes and SRI instructors "must not attempt to convert students".

The state's largest SRI provider, Access Ministries, has described the new policy as "ambiguous and confusing".

"When we sing a Christmas carol, that is based on a biblical story. Do you need permission to sing a Christmas carol?," Access Ministries spokesman Rob Ward asked.

But Fairness in Religions in School spokeswoman Lara Wood said the new policy would make schools more inclusive.

She said principals and parents needed to remain vigilant to ensure there was no proselytising. "We know from past experience that the program has been badly managed."

The state government has provided principals with a list of scenarios to ensure they understand the difference between an SRI and non-SRI activity.

For instance, students can take part in a course on Jewish history during class time with the support of the Jewish Museum of Australia.

Prayer groups led by students are also considered a non-SRI activity, as long as no one from outside school is present.

"A secular education is not devoid of everything that has a spiritual element," the advice says.

It then goes on to say that a mandala, an important part of Tibetan Buddhism, can be used in maths  to learn about shapes and symmetry, and in art.

Schools can also put up Christmas decorations and display a Menorah because these items have "a secular cultural place in Australian society".

But they are not allowed to display religious material.

Australian Education Union Victorian branch president Meredith Peace welcomed the changes, which she said would result in many schools scrapping SRI entirely.

"The most common concern raised by our members was that these programs were taking up valuable class time in an already overcrowded curriculum."

She said schools understood what it meant to be secular, and were unlikely to be confused by the new rules.

Education Minister James Merlino said secular education still included education about world faiths and secular belief structures.

"As with other curriculum decisions, schools will make the decision as to which Christmas carols feature as part of classroom activities."