Digital Object Identifier (DOI) is an identification system for the document published digitally on internet. It is a very important tool of the digital database. DOI system is particularly useful for electronic documents like research articles. Research articles can be easily identified by the assigned DOI number published on internet.

DOI is an alphanumeric string that identifies content and provides persistent link to its location on internet. Its main purpose is to help users find relevant information about resources and provide digital identification. Users can easily find location of digital object through metadata used in the system.

The INREIN-DOI (Index Research International-Digital Object Identifier) is a unique alphanumeric string consisting of two parts, prefix and suffix. Prefix (e.g. inrein.com/10.4444/2011.1001) identifies the registrant and suffix indicates the object associated with that name (e.g. specific content to be identified).

INREIN-DOI system is created by a registered organization to help scientific world to know more about digitisation of materials. Example: inrein.com/10.4444/2011.1001

INREIN-DOI is very helpful for publishers and readers to identify digital object published online. Location of electronic files may change over time but INREIN-DOI remains fixed permanent. INREIN-DOI system provides framework for persistent identification, management of metadata and linking among users. INREIN-DOI can be used to cite journal articles. This is generated once article is published online to provide exact information about the content.