Q:

Name for bracket used for holding shift cables in place on down tube

I've got a '70s-era Motobécane† road bike which doesn't have any actual eyelets brazed on for guiding shift cables but instead has a strange chromed "bracket" which attaches onto the down tube with a screw and washer which has two small guides for keeping the shift cables in place (highlighted in green):

What on Earth is this thing called? —  I've never seen something like this before. 

† Actually, it's a Motoconfort, but I still haven't been able to discern any real differences between the two marques despite trying my best to do so. 

A:

Several on line searches for "cable stops" have yielded numerous results so I guess the term is universal.  They are available in single, double and triple cable models.  Another variation is a "cable clamp", it function is to attach the cable housing to the frame.  You will need to measure the frame tube diameter to get a clamp that will fit the frame.