It's hard to say. The concept is very old. I would start with the related link article on Wikipedia.
5
India
India
In 1961, the office of the Postmaster General (PMG) introduced the 000 number in major population centres.
rational numbers invented by mathematicians
given a number and title.
400
Once introduced by the House secretary, it is given a number and short title by the clerk of the House.
After a bill is introduced in either the House or the Senate, the bill is assigned a number.
PIN stands for Postal Index Number and the code is 6 digits long. The PIN was introduced on August 15, 1972.
15
Be more specific and I'll answer it- Sold or introduced?