The need to strike a balance between welcoming anonymous donations and providing transparency as a public agency divided the Palo Alto school board on Tuesday night, with its members ultimately approving in a 3-2 vote a new requirement for internally disclosing donors' identities.

People or organizations who give the district more than $50,000 and wish to remain publicly anonymous will now have to disclose their identity to the superintendent, who would then inform each board member verbally, one by one. The board can waive this requirement in public session.

Newly elected President Ken Dauber, Vice President Jennifer DiBrienza and board member Terry Godfrey supported the new policy, arguing that the board should know who donors are in case there is any reputational or financial risk to the district. The waiver, they said, provides public accountability to the board's decision to accept or reject an anonymous donation.

Board members Melissa Baten Caswell and Todd Collins cast the dissenting votes. Collins said he could not support building into policy what he described as a "clever" workaround for open-meeting law the Brown Act, which prohibits board members from talking to more than one other trustee about district business outside of a public meeting.

"We've basically gotten around it by saying the superintendent will go to each person one at a time and tell them," Collins said. "Then the question is — that's a clever idea; what else can we do to get around the Brown Act?"

Baten Caswell said she was "uncomfortable" with the proposal's potential to make board members feel "beholden" to someone who gives a large sum of money to the district. She was more supportive of working with a vetted donor-advised fund that protects the person or organization's identity.

The other members disagreed with Collins' characterization of the policy as an evasion of the Brown Act. DiBrienza said conversely that she thinks ensuring the board members and superintendent know a donor's identity would increase transparency and accountability.

The policy was spurred by a significant anonymous donation made to Addison Elementary School last year. A third-party representative for the donor approached the school district in 2015 to communicate the donor's interest in making a "substantial" contribution toward renovating aging facilities at Addison.

Though the project has moved forward, with the board accepting the first two of what is expected to be several donations and a firm drafting design plans, it has hung in the balance in some ways as the board debated the question of donor identity over the last year-plus.

At the urging of Addison Principal Amanda Boyce on Tuesday, the board voted to make no attempt to ascertain the identity of the project's donor since he or she initiated the gifts before discussions began over the new policy.

Dauber said he is not fully comfortable with the policy as it stands, but including the waiver is the best way to enable the district to accept anonymous donations and maintain public accountability.

"My belief actually is to the extent that we receive anonymous donations in the future, we will most often waive the requirement that we be informed of the donor's identity. But each and every one of those votes will be an opportunity to have the discussion and to weigh the costs and benefits and to do it in public," he said.

In other business Tuesday, the board elected its new president and vice president for 2018: Dauber and DiBrienza, respectively.

The board also postponed approving a comment letter on Santa Clara County's draft environmental impact report on Stanford University's proposed general-use permit application. The county recently extended its comment period to Feb. 2 at the request of several local agencies, including the school board and Palo Alto City Council.