A buck is a $1 the ding ding ding Is a free envelope that is free. It means every time a savings challenge is completed you ring the bell and add $1 it’s like a extra savings
Dollar bills have letters on them showing what facility they were printed in. A "b" buck was printed in the facility designated with a "B" ding ding challenge is from Donna by creativity I think is the name. When someone in the savings community rings a bell for finishing a challenge they save $1
The US $1 bills have a letter of the alphabet on them. It doesn't apply to Aussie dollars (we have coins for $1 anyway). The ding ding challenge is to celebrate finishing a challenge.