How can I specify and encode item numbers into a RAIN RFID tag and what is "Acid RAIN"?

The item number is a unique identifier of the item the tag is attached to. The item number can be defined with the following methods:

• Standard-managed item number schemes

The Electronic Product Codes (EPC) developed and administered by GS1 (GS1 EPC Tag Data Standard). GS1 also published a set of standards to support the use of EPCs which includes a reader interface and the EPC data stack. 

ISO item number schemes (Unique Item Identifier - UII) are specified by registered organisations, like IATA or RAIN Alliance. They are administered by the ISO Registrar AIMglobal (ISO/IEC 15961).

• Self-managed item number schemes

ISO/IEC 20248 is an ISO item number scheme which allows ISO/IEC 15459 registered companies and organisations to develop and manage their own item numbers and tag data.

Standards compliant (Standard-managed and Self-managed) tag data ensures that there is no interference with any other standard tag data, be it GS1 or ISO tag data. Tag data interference results in proprietary number schemes where no rules are followed. In consequence, tags of different applications can appear to belong to another application; as such they may cause undesirable results. This is called “Acid RAIN”.

It is important to note that even the smallest RAIN enabled application may become a big and highly successful application that can interfere with other applications.