Mnemonic maps associate signal values with strings, colors, line shapes, and icons. For example, you can define a mnemonic map to associate a name with each state of a state machine, or you can define a mnemonic map to display all x values with a background color of your choice.
When you create an analog mnemonic map, you define not only the text that is displayed for a signal value, but also a background color of the waveform in the SimVision Waveform window.