In a number of Telegraph Stations, especially those officially designated as Repeater Stations, telegraphic messages were received which had then to be relayed immediately to another station. This on-forwarding was necessary either because:
In these circumstances, the incoming message was written out and then the operator would tap out the message again in Morse Code and send it to the next appropriate station - either to the nominated destination or to the next repeater station. Technical developments did lead to the message being recorded directly on to tape which could then be fed into a sending machine and thus avoid the manual coding.
At first the message received at a repeating station was simply written on to a piece of paper available in the office. These papers varied in size, condition, condition and nature of previous use if any.
The first two South Australian forms issued at the beginning of the Interim period carried the note in the top left corner that they were to be used as a "Delivery or Transit Form" - see SI-DO-1 or SI-DO-2.
The 1921 Postmaster's Instruction Book noted:
"Telegrams received for onward transmission must be written on blank "transit" forms. The backs of used documents which have been kept for the prescribed period may, provided they are of suitable size, be utilised for this purpose".
On 12 May 1922, this instruction was amended to "Telegrams received for onward transmissions must be written of "received" telegram forms".