Unique identification number
A Unique Identification Number (usually abbreviated as UIN ) is a combination of digits or characters with which hardware and software, people, communication, objects or general entities within a certain category can be clearly identified. The assignment of the numbers must be done in a way that excludes the multiple assignment of the same number for different entities. A reversible, unambiguous relationship is also often required.
UINs are primarily used to ensure the simplest possible identification ; an alternative would be to use attributes . When using attributes, however, one encounters problems of under- or over-definition (cf. entropy ). If in doubt, you have to specify all conceivable attributes in order to achieve reliable identification. In contrast to this, a UIN represents a unique characteristic. Often a combination of a conditionally unique identifier and attribute is used, for example with the help of time stamps .
Examples
- in relational databases the primary key
- the user ID in interaction systems (e.g. with ICQ IM)
- the electronic product code in merchandise management systems
- the ID number or personal identification number (e.g. personal identification number for the Bundeswehr)