Daniel MacPhee, manager of the Yale Farm, once had to chase down a bus full of schoolchildren who had come to volunteer for the day but could not find the farm. But he could not blame the driver — the farm has no sign.

Yale Farm administrators’ requests for one of Yale’s iconic blue porcelain plaques are meeting resistance from the University Printer’s office. While MacPhee and his colleagues said they would like a sign to help visitors find the farm more easily, University Printer John Gambell said that in keeping with his “visual program” for the University, signs are for buildings only.

Yale’s exterior signs are part of an extensive and codified system that has been in place since 2000, Gambell said. Under the current criteria, the Yale Farm, which broke ground in 2003, does not qualify for this kind of official signing because it is an exterior space. Like Old Campus, Cross Campus and Beinecke Plaza, the Yale Farm is only named on pedestrian and online maps.

“The fact that there are greenhouses and plants growing makes it clear you are at an agricultural facility,” Gambell said. “A blue porcelain sign gives an element of status to that facility.”

But without an official sign to guide them, students, visitors, passersby and people making deliveries often have trouble figuring out where the farm is, MacPhee said. Besides the school bus, he occasionally finds himself flagging down delivery trucks that are uncertain of the farm’s exact location, he said.

“Throughout the day, people are always walking by and asking, ‘Is this a community garden? Am I allowed to be here?’ ” he said. “I think people don’t necessarily know that it’s attached to Yale at all.”

The farm is open to the public and regularly holds workdays when students and members of the community can volunteer at the farm, and it hosts events such as pig roasts. MacPhee said the Yale Sustainable Food Project, which runs the farm, relies on posters and word of mouth to make sure the Yale community knows the farm is open and active.

But a sign would be helpful for New Haven citizens who might not know about the farm otherwise, MacPhee said.

“We make a big deal about always being welcoming to anybody,” he said. “We invite [curious passersby] in and explain what the farm is and what the project is about. But it’s me using those words with each individual person, as opposed to someone seeing a sign. And I can’t be here all the time.”

If the farm were to receive a sign, it would have to be a different design, Gambell said. The current aesthetic scheme for Yale has a certain unity, he said — “an affirmation for visitors that they are on the Yale campus.”

“There is an effort to unclutter the visual program,” Gambell said. “We’ve installed fewer, better-designed signs. There is a less-is-more principle at the top of the list.”

Melina Shannon-DiPietro, the director of the YSFP, said she understands the desire to protect the Yale brand and visual identity. The sign is “on the back burner” for the time being, she said. But the YSFP and Office of the University Printer will be continuing discussions, and Shannon-DiPietro hopes to have one by the spring.

Until then, the farm does not seem to be suffering from lack of exposure due to the abcense of a sign, Shannon-DiPietro said. Between 100 and 150 people attended workdays in September and October, and the farm hosted a harvest festival in October with roughly 200 people in attendance, she said.

Gambell said that, if necessary, the final word about a sign for the farm may lie with the Office of the Secretary. University Vice President and Secretary Linda Lorimer said Tuesday that word of the dispute has not yet reached her office.

Correction: Dec. 2, 2009

Due to an editing error, an earlier version of this article misstated who submitted the request for an official Yale sign. Melina Shannon-DiPietro, the director of the Yale Sustainable Food Project, and another colleague requested the sign, not Farm Manager Daniel MacPhee. The farm is, in fact, scheduled to have a Yale address sign in place this spring.