||The name of the variable.
|| Set this value to 'yes' in order to make the variable's value overridable either by another WixVariable entry or via the command-line option -d<name>=<value> for light.exe. If the same variable is declared overridable in multiple places it will cause an error (since WiX won't know which value is correct). The default value is 'no'.
|| The value of the variable. The value cannot be an empty string because that would make it possible to accidentally set a column to null.