Sime is the umbrella term for all the various mutations of sime including the channels and renSimes. RenSime, a Sime who is not a channel, has only one selyn system for personal consumption. Also referred to as a 'normal Sime,' 'renSime' is a term coined to differentiate channels from the 'common' Sime. Before channels the general population only referred to themselves as Sime.
A renSime has only the one selyn system that is utilized for the sole purpose of sustaining the Sime's life. Sime bodies operate on selyn, not calories. Simes eat only to replace body-building materials.
From Index Card, dated June 17, 1977 --- Difficult for Simes to “pass” as Gens out-Territory --- recognized by walk, demeanor, gracefulness, quickness, accent. It would take a supreme actor to carry it off.