Attention TTC customers: A Toronto woman has come up with a simple, quick and polite way for people with episodic or invisible disabilities to ask for a seat when riding the transit service.

It's called Equity Buttons.

Kate Welsh, who defines herself as an activist, artist and educator, told Metro Morning this week that she designed the buttons to make taking public transit easier for people who sometimes look well but often are not.

Episodic disabilities are characterized by periods of wellness and periods of illness. Episodes can vary in length, severity and predictability. Examples include HIV, chronic pain, multiple sclerosis or fibromyalgia.

"Some days, I'm having a good day and I'm okay standing, and some days, I'm having a bad day and I'm not feeling well and I really need to sit," Welsh said this week.

The buttons come in blue, green and purple. They say: "Please Offer Me a Seat" and "My Disability is Episodic" or "My Disability is Invisible." (Muriel Draaisma/CBC)

"As a young person, I often am not offered a seat if I need a seat, so I created this initiative for people like me."

The buttons, which come in blue, green and purple, say: "Please Offer Me a Seat" and "My Disability is Episodic" or "My Disability is Invisible." Some feature only text, while others include a graphic of a person holding a graph with a line that goes up and down to signify the unpredictable nature of the disability or illness.

"I have asked for a seat and been given a long pause," Welsh said. "And then someone else offers me one instead. I have been questioned, like, 'Prove it.' "

Welsh said the idea for the buttons came when she helped a friend with cancer who needed to sit after treatments when on the TTC. Welsh created a homemade button for her using a Sharpie marker. It read: "My Disability is Invisible."

"She expressed to me the frustrations of needing a seat, then sitting, then having other folks come in and tell her to move and get up," she said.

'Somedays, I'm having a good day and I'm okay standing, and somedays, I'm having a bad day and I'm not feeling well and I really need to sit,' says Kate Welsh. (Yas Salame)

Now, with the help of a colleague, Welsh designed the buttons now for sale in a few local bookstores, health food stores and online.

She said the buttons have had a positive effect, and in many cases, people don't even have to ask for a seat. TTC riders will see a button and simply offer one.

"I've heard stories of people saying that they feel more confident sitting and taking up space that they need to take up."

And the buttons themselves are designed to help raise awareness.

"I started this initiative as a very practical thing. I would like our society to understand that disability is not just about a wheelchair or a cane. Disability can depend on the person's experience," she said.

There are five different types of Equity buttons. (Muriel Draaisma/CBC)

Stuart Green, spokesperson for the TTC, said the transit agency has no problem with the buttons.

"If people wish to wear a button that passively asks for a seat for any reason (pregnancy, disability), that is absolutely their right," he said in an email. "People, of course, can also politely ask for a seat if they feel comfortable doing so."

Green said the TTC has blue priority seats designed for people with disabilities and riders are urged to use priority seating properly. The TTC is currently running a campaign that reminds people to give up blue priority seats for people who need them.

And it is monitoring a similar campaign in the U.K., by Transport for London, that involves a button and card for people who need a seat because they have impairments, conditions or illnesses, short term or long term.