The phrase "symbol key" refers to a set of symbols that help you understand or decode something. It's like a special set of images or icons that provide clues or explanations. Full definition
Direct students to record this color / symbol key in their science notebook. (teacherstryscience.org)
These include a four - way directional keypad on the left, dual analog touch joysticks in the center, and four familiar PlayStation symbol keys (circle, X, triangle, square) on the right. (laptopmag.com)
Customers easily become gamers with the slide out game pad revealing a directional keypad, dual analog touch joystick, two shoulder buttons and the four iconic PlayStation ® symbol keys: circle, X, square and triangle. (bgr.com)