Proceed-to-select

Proceed-to-select: In communications systems operation, pertaining to a signal or event in the call-access phase of a data call, which signal or event confirms the reception of a call-request signal and advises the calling data terminal equipment to proceed with the transmission of the selection signals.

Note: Examples of proceed-to-select pertain to a dial tone in a telephone system.

Source: from Federal Standard 1037C