ICQ#UIN

A Unique Identification Number ( UIN usually abbreviated, dt: unique identification number ) is a number or character combination that can be objects, people, or in general uniquely identify entities within a particular category. The assignment of the numbers must be carried out in a manner that excludes the multiple award the same number for different entities. Frequently, a reversible clear relationship is required.

UINs is used primarily to ensure the easiest possible identification, an alternative would be the use of attributes. When using attributes, but one encounters problems of under-or over -definedness (see entropy). If in doubt, you have to specify all conceivable attributes to achieve reliable identification. In contrast, a UIN a unique feature dar. Often also used a combination of conditionally unique identifier and attribute, perhaps with the help of time stamps.

Examples

• In relational databases the primary key
• In interaction systems, the user ID (eg ICQ)
• In ERP systems, the electronic product code
• The card number or personal identification number (for example, personal identification number in the army )