Some of the world's most recognizable symbols exist to sell products, others to steer traffic or advance political causes.
But there's one whose main purpose is to help people.
You may know it as the wheelchair symbol, or a sign for people with disabilities, but its formal title as maintained by the ISO is the International Symbol of Access.
But despite its familiarity, many people are unclear as to what the symbol actually means, which has a lot to do with the symbol itself and the way it came about.
In 1968, the International Commission on Technology and Accessibility held a design contest.
They were looking for a symbol that would be readily identifiable from a reasonable distance, self-descriptive, simple, practical, and couldn't be confused with existing signage.
The winning design, which didn't have a head, was created by a Danish designer named Susanne Koefed.
The addition of a head a year later gave it a more human form, and within ten years, it was endorsed by both the United Nations and the ISO.
With minimal cost and minimal fuss, a global icon was born. There have been a few tweaks over the decades.
The Graphic Artists Guild added more rounded, human-like features, and in 2012, the Accessible Icon Project produced a more dynamic version.
But what does it really represent? What's its purpose?
Put simply, it's a sign to identify where there are accessible facilities.
The strength of such an internationally recognized image is that wherever you travel, you don't need to speak the language or have in-depth cultural knowledge.
If you require an accessible toilet, the sign shows the way. But the confusion comes from the term accessibility and what that actually means.
Many people assume that because the symbol depicts a wheelchair, that accessible facilities are meant only for people who use wheelchairs, or those, at the very least, who have a visible physical condition.
But accessibility is a broad concept that applies to many, many different conditions.
That includes people with autism, visual impairments, and autoimmune diseases, like lupus, which can cause pain and fatigue, along with many other conditions.
In fact, the World Health Organization estimates that there are approximately 1 billion people who experience some form of disability, which means that this group is very likely to include yourself, or a family member, a classmate, a friend, or a work colleague.
And people who use wheelchairs only make up about 65 million, or 15% of the total. The vast majority have non-visible disabilities.
Accessible parking spaces, facilities, and entrances are designed with that entire group in mind.
So it's easy to see why in recent years people have begun to raise questions about whether the symbol is really appropriate for what it's meant to do. And it's not just about accuracy.
It's common for people to become indignant, sometimes abusive, when they see people without visible disabilities using accessible facilities.
The symbol is unfortunately creating widespread issues for the very people and families it's meant to help.
The recent redesigns have attempted with some success to acknowledge concerns over the current symbol. But some think that a complete redesign is in order. It's a difficult task, though.
How do you replace a symbol that's familiar the world over? And what do you replace it with?