The male and female symbols together usually indicate a unisex toilet.
A unisex public toilet, or unisex toilet, unisex bathroom, family toilet, or gender-neutral bathroom, is a public restroom or toilet that people of any gender or gender identity may use; this definition family restrooms for family or elderly use. Developers may use such restrooms to save costs and space by eliminating the need for a separate facility; e.g., airliners, trains, or buses, unisex toilets are used.
Unisex restrooms are adopted in the US primarily because increasingly many elderly couples include a person whose mobility issues necessitates the other's assistance. Furthermore, transgender advocacy groups in the United States promote unisex restrooms, believing that they eliminate harassment and other inconveniences that transgender and gender non conforming people experience when using binary gendered bathrooms.