The singing group the Baker’s Dozen has violated regulations governing a cappella rush by allegedly serving alcohol to rushees.

The Baker’s Dozen is the only a cappella group to be punished under new rush regulations so far this year, co-chairmen of the Singing Group Council confirmed Monday evening. The group will be forced to miss the Woolsey Hall jam next year and to wait an additional two minutes at the High Street gate before this year’s tap night because they allegedly served alcohol to rushees at a party following the group’s Friday singing dessert.

Dean of Student Affairs Marichal Gentry said his office is not currently involved in the situation.

“We only get involved when there’s a dispute with the singing council,” Gentry said.

But Gentry acknowledged that serving alcohol to minors violated both undergraduate regulations and Connecticut state law, and that the Dean’s Office could shut down the Baker’s Dozen if “the group had done something in violation” of those regulations.

Stephen Feigenbaum ’11, a member of the Baker’s Dozen, declined comment on behalf of the group.

After four groups violated rush regulations last fall, the council retooled rush regulations over the summer to ensure better enforcement and to further elaborate on what sorts of meetings with rushees are acceptable.

The restrictions — which include a ban on serving alcohol to rushees and engaging in rituals that the council has not pre-approved — are not new, but the punishments for violating them have become more severe. Those revised regulations, e-mailed to groups over the summer, include a stipulation that groups can be banned from performing at the Woolsey jam if they violate alcohol rules.

“[The Woolsey Jam is] the first institutional introduction to a cappella for freshmen in the fall,” council co-chairman Jeff Hudson ’10 said. “We consider it sort of a big deal if a group can’t perform there.”

Last year, Proof of the Pudding, Baker’s Dozen the Society of Orpheus and Bacchus allegedly violated alcohol regulations. Hudson said the SGC has no knowledge of any of those groups serving alcohol at rush events so far this year.

A cappella tap night is scheduled for Monday, Sept. 21.