Personal ID Numbers in Sci-Fi

When he had filled out all the homesteading forms he had of course put down his phone number, since this was as much a part of him as was his name. Everyone was given a phone number at birth, and it was his for life. With the computer-controlled circuits anyone, anywhere on a planet, could be reached by the dialling of a single number. But who could be calling him here? As far as he knew, only Lea Davies had his number.
The Men from P.I.G and R.O.B.O.T, Harry Harrison.
Dr Wallace laid the palm of her hand upon the plate, then removed it after a few seconds. She glanced at Poole, and said smilingly: 'Come and look at this.'
The inscription that had suddenly appeared made a good deal of sense, when he read it slowly: WALLACE, INDRA [F2970.03.11 :31.885 / /HIST.OXFORD] 'I suppose it means Female, date of birth 11 March 2970 – and that you're associated with the Department of History at Oxford. And I guess that 31.885 is a personal identification number. Correct?'
'Excellent, Mr Poole. I've seen some of your e-mail addresses and credit card numbers – hideous strings of alpha-numeric gibberish that no one could possibly remember! But we all know our date of birth, and not more than 99,999 other people will share it. So a five-figure number is all you'll ever need…
3001, Arthur C. Clarke
Clarke’s proposal is an elegant starting point for creating a personal universal identification code (UID). Some comments are in order, however.
In Clarke’s book, the human population is only a billion, system-wide. A five-figure number may not be adequate for larger populations, such as the eleven billion or more of Transhuman Space. Most humans can remember seven-digit numbers. In earlier generations, most people memorized their own seven-digit phone number and a few others that might be often used or belonged to friends.
A valid question is what would happen to Dr Wallace’s ID number if she decided to change sex. Would she/he be issued a new number where only the date of birth remained the same? Would the older number remain valid, allowing colleagues unaware of her/his life change to get in touch. What happens if Dr.Wallace decides to revert to being female?
Some individuals may prefer not to be identified by their physical-sex-at-birth. The universal identifier code may also be used by AIs and other infomorphs that are neither male nor female. To the M and F prefixes we may see at least two others: N for “neuter (non-carbon)” intelligences, and C for “common (epicene/ physical sex unspecified)”.
The five/seven digit numeral component of the UID code may be further distinguished by a letter prefix indicating where the individual was born. For those born on the Moon this will be an “L” for Luna, for Mars an “M”, “B” for the asteroid belt, and so on. Individuals born on or near Mercury will have a “H” from Hermes, although in the THS-era there will have been very few births there. Earth, however, has a population in the billions, so it may be prudent to subdivide Earth (E) by continent: North America (EN), South America (ES), Europe (EU), West Asia (EW), East Asia (EE), Africa (EA), Pacific and Australasia (EP), Antarctic (EK). This would include an identifier for those born in Earth Orbit (EO). Individuals born around Jupiter or Saturn may have an identifier that includes which moon they were born on or near. For example, babies from Titan have an “6S” designation since Titan is the sixth moon of Saturn.
To make ID number length consistent, single-letter planetary codes are preceded by a zero. This gives the option of expanding these to two letter codes when planetary populations have grown.
For obvious reasons, the ID number is referred to by such terms as “eighteen”, “eighteen bits” or “eighteen digits”.
Various systems of numerology and fortune telling may utilize the UID to separate the credulous from their money.

by M1966:05:26 EU644.5007