This object specifies the backward signal requesting either a language-selection digit for operator-assisted calls or a discriminating digit for automatic calls, per the R2 spec's dual use of this signal. Which of the two meanings applies depends on whether the call is operator-assisted or automatic, so an admin interpreting logs involving this signal needs to know the call type in context to know whether it is a language request or a routing-discriminator request. On an automatic international call, this signal might be used to request a discriminating digit that tells the gateway which of several possible routing tables to apply to the remaining digits.