Robert P. Munafo, 2008 Feb 22.
The "non-member" points, also called the exterior of the Mandelbrot set, are those that escape when iteration is applied to them. In images these are usually assigned a color based on dwell value.
From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2018. Mu-ency index
This page was written in the "embarrassingly readable" markup language RHTF, and was last updated on 2018 Feb 04. s.11