I do not know if this is the right place for egl queries...

Even though a given configuration is non-conformant, the application renders successfully.

What does the "EGL_CONFORMANT" attribute actually convey?

code snippet:

eglGetConfigAttrib( display, config, EGL_CONFORMANT, &conformant);
if(conformant & EGL_OPENGL_ES_BIT)
printf("Conformant configuration\n");
else {
printf("NON CONFORMANT CONFIGURATION\n");
}