Publisher Item Identifier

The Publisher Item Identifier is a unique identifier used by a number of scientific journal publishers to identify documents. It uses the pre-existing ISSN or ISBN of the publication in question, and adds a character for source publication type, an item number, and a check digit.
The system was adopted in 1996 by the American Chemical Society, the
American Institute of Physics, the American Physical Society,
Elsevier Science, and the IEEE.

Format

A PII is a 17-character string, consisting of:

one character to indicate source publication type: "S" = serial with ISSN, "B" = book with ISBN
ISSN or ISBN of the serial or book to which the publication item is primarily assigned
in the case of serials an additional two digit number to pad the difference between the 8-digit ISSN and an ISBN
a 5-digit number assigned by the publisher that is unique to the publication item within the serial or book
a check digit

When a PII is printed, the 17-character string may be extended with punctuation characters to make it more readable to humans, as in Sxxxx-xxxxiiiii-d or Bx-xxx-xxxxx-x/iiiii-d.

Example

The PII - can be broken down as, where

- Indicates the publication is a serial, not a book
- for the publication Bioorganic & Medicinal Chemistry Letters
- Padding/Year Code
- Publisher's internal number
- Check digit

This is the PII for a scientific paper by Silvie Géhanne et al.:
*

DOI

PII codes can be used as the item ID in a DOI identifier. In the previous example, the number 10.1016 is the DOI's publisher ID, a slash acts as a separator, followed by the PII code S0960-894X00515-X.