Based on Northern Telecom (Nortel) Harmony
That Ireland map phone was based on the chassis of a very standard issue Nortel Harmony phone that were one of their more popular rental models in the 1980s. I still have one plugged into VoIP and it works a charm despite being probably close to 40 years old.
Also including a photo of another common model that was rented here in the 1980s. Can’t remember what Telecom called it, but it was quite a famous Danish design, and I think manufactured by a Kirk.
The “R” (Recall) button is the hook flash for call waiting / 3 way calling. The timing is a bit different to the US and closer to pulse dialling 1.
If you used the “Flash” button on a US phone on an Irish landline it was too long and cleared the line, as it was interpreted as hanging up by the switching system.
R1 = answer incoming call waiting & hang up on current call.
R2 = toggle between calls.
R3 = conference call.
If you wanted to add a call, you dialled “R” which put the call on hold and gave you a dial tone. Then made the second call and R1 / R2 / R3 could be used to end one call, toggle between or merge the calls.
A lot of late phones had at least R 2 stored on a button.
A lot of European PSTN switches did it that way.
