AI 30 is used to specify a number of pieces in a weight variable ordering unit, where the number of pieces varies.
AI 30 should always be used in conjunction with AI 01 for GTIN number. The weight-variable product shall be identified by a GTIN-14 starting with the digit 9.
Application Identifiers for Measurement Units
This section describes the Application Identifiers that exist for unit of measurement. The AIs consist of 4 digits, where the value of the 4th digit (n) indicates the number of decimal places.
The data format for all the AIs is n4+n6.
Example:
(310)! 0) 000035 = 35 kg
(310)! 3) 000035 = 0.035 kg
The 4th digit (n) can be from 0-9, meaning that smallest unit one can specify is:
(310)! 9) 000001 = 0.00000000001 kg
GS1 recommends the metric system (SI system - International System of Units). If other systems are used, it should be noted that there may be a difference between targets in the US and the UK.
The AIs from 3100 to 3699 indicate different types of units of measurement related to trade or logistics.
AI 3nnn (2) shell appear together with AI 01 or AI 02 where the 1st digit is 9.