Wolfgang Van Rosan's seven-year-old daughter was feeling "depressed" one day last week when she came home from her school in Oakville.

The second grader was so sad, Van Rosan said, she couldn't study for her spelling test.

It took some coaxing, but Van Rosan found out what had triggered the girl's melancholy.

"She said, 'Well, today, one of my classmates came around during recess, and she started handing out invitations, and a few of us didn't get one,'" he said on Metro Morning.

"She felt very rejected."

In the grand scheme of problems that families grapple with, birthday invitations don't typically rank at the top of the list. But they can cause plenty of stress for children who don't get invited to the party.

So how do you protect a little girl or boy from feeling upset when they don't get selected to attend a party?

In his daughter's case, ​Van Rosan emailed the school's teachers and principal to ask about the procedures around birthday invitations. The principal wrote back saying that, yes, this was a violation of school policies.

"Especially at this age, [the birthday girl] is giving invitations to some and not to others. This creates a two-tier classmate system: those invited and not invited," he said.

This is a privilege, not a right, to hand out invitations in a public place. - Parent Wolfgang Van Rosan

Some parents, Van Rosan among them, believes there needs to be a specific policy in which students must invite everyone in the class, or they invite no-one. But Van Rosan said there should be a consideration for gender, as many second graders will want a girls- or boys-only party.

"However if you are going to discriminate, based on...whatever, and only invite certain people from the class, that's something that has to be approved by the teacher," he said.

"This is a privilege, not a right, to hand out invitations in a public place."

Anjum Choudhry Nayyar, the editor-in-chief of Masalamommas, an online magazine for mothers, empathizes with Van Rosan.

Children should be able to handle the rejection that comes with being invited around the age of 10, Nayyar said. But before that age, her daughters' parties adhere to the all-or-none approach, or she will defer to the teacher to hand out the invites.

Invitations could be made outside the classroom, but often there are privacy concerns around sharing parent contact information.

"We really have to teach our kids to have some kind of understanding that they are going to get rejected, that they're not going to get invited to every party. As an adult ... you don't get invited to every cool event," she said.

"But there is a certain time and place for that."