Another school supplied an entire folder detailing achievements and areas in need of improvement.
Newmarket School principal Wendy Kofoed did a doctoral thesis on the language of reports.
She said she constantly reviewed her reports to make sure they were easy to understand.
"Clarity is still the big issue in the language we use."
Kofoed said reports with many levels, ages, and stages could be confusing.
"We're providing so much information that it is making reporting in some cases less accessible for parents who want to know their children are doing well and are making progress.
"We can convey that reasonably simply."
Lynda Harris, founder of the Writemark Plain English Awards, is also a former teacher.
She said a layer of technical language was now part of education.
"It isn't just in the language of reports.Those technical terms are used in the classroom daily."
Children routinely spoke a "foreign language" to their parents about their own learning, Harris said.
Student achievement was measured against National Standards but the Education Ministry said it had no plans to standardise reports.
Deputy secretary of student achievement, Rowena Phair, said schools could report on progress to parents in whatever way they considered appropriate, using "clear and easily understood language".
"The ministry provides guidance for schools on how they might report to parents, which includes examples of good practice," she said. "There are no plans to require schools to standardise how they report to parents about their child's progress."
The ministry estimates 62,000 new entrants will start school during the 2014 year.