[InCityDreams]

Good history here (and, you're not incorrect) - https://en.wikipedia.org/wiki/Passport : modern passports 1920s.

"While the United Nations held a travel conference in 1963, no passport guidelines resulted from it. Passport standardization came about in 1980, under the auspices of the ICAO.

ICAO standards include those for machine-readable passports.

Such passports have an area where some of the information otherwise written in textual form is written as strings of alphanumeric characters, printed in a manner suitable for optical character recognition.

This enables border controllers and other law enforcement agents to process these passports more quickly, without having to input the information manually into a computer."

[skissane]

A lot has changed about passports even in my lifetime (I’m in my early 40s). I remember my mother showing me one of her old British passports, which had my younger brother on it.

The UK abolished family passports in 1998, so since then it has been impossible for a person to add their spouse or minor child to their British passport, your spouse/child needs a British passport of their own-even a newborn baby

Whereas, our other nationality, Australian (I, my mother and my siblings are all dual Australia/UK citizens), I’m not sure if it ever had family passports, but if it did, it must have abolished them significantly before the UK did