Also used in Bash, ruby, R when referencing elements of a list…

I’m going to guess the GP didn’t want to give their kid’s name here and decided not to insert a generic Billy in its place. So this being a forum with lots of people experienced in $programming_language it’s common to reference a generic placeholder in variable syntax.

Personally, I think comments on HN should use properly type safe syntax, in which case $CHILD is replaced by:

    with Ada.Strings.Unbounded;
    use Ada.Strings.Unbounded;

    Name : Unbounded_String;