Innermost workings of CTA explained: What do 1, 3 and 6 beeps from fare cards mean?

The article isn't entirely clear what cards apply for the one beep, so i'm labeling it "all cards" Here's my summary list:

For all cards:
--1 beep: valid transaction.

Chicago Card, RTA reduced-fare smart card or student permit smart card:
--3 beeps: the word "Retouch" on the farebox indicate the fare card machine was unable to read the card and the customer should retouch the card
--3 beeps: without the "Retouch" prompt indicate the card has been accepted, but it has less than $2 of value remaining.

Chicago Card Plus:
--3 beeps: the fare has been collected.

For all cards:
--6 beeps: the fare has not been paid because of an invalid or expired card,