They may be man’s best friend, but not all dogs are people dogs.

Some canines may be easily frightened or aggressive. Others might simply be undergoing training or require extra space as they recover from surgery.

German shepherd underoing trainingThanks to the Yellow Dog Project, such dogs now have a way to communicate this.

The idea is simple: If your dog doesn’t like to be approached, tie a yellow ribbon around his collar or leash to signal that your pet needs some space.

Tara Palardy, a dog trainer from Innisfail, Alberta, founded the Yellow Dog Project in 2012 to raise awareness that not all dogs are social.

Palardy got the idea for the Yellow Dog Project from a Swedish website, but she wanted to take her yellow ribbons worldwide.

She created a logo, launched a website and started a Facebook page that’s attracted more than 20,000 followers.

However, the Yellow Dog Project is still working to get its message out.

Claudia Kawczynska, editor in chief of The Bark magazine, says she’s in favor of a do-not-approach indicator for dogs, but she thinks it will have a hard time catching on some places.

"It's expecting a lot out of people," she told USA Today. "Most dog people are very outgoing people because they love dogs and love their dogs to love other dogs."

Laura Moss writes about a variety of topics with a focus on animals, science, language and culture. But she mostly writes about cats.

What is the Yellow Dog Project?
The project was created to raise public awareness about timid dogs and canines that require space while training or being rehabilitated.