EPPML (Extensible Postal Product Model and Language) is a
conceptual model
A conceptual model is a representation of a system. It consists of concepts used to help people know, understand, or simulate a subject the model represents. In contrast, physical models are physical object such as a toy model that may be assem ...
for the interactions between parties of a postal communication system. Examples of such parties are mailers, posts, mail aggregators, providers of
postal services
The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...
and equipment and recipients. They create, publish, consume and deliver postal products.
The central concept of EPPML is the postal product. EPPML defines the structure and meaning for the information that represents a postal product. The postal product definition may be viewed as an interface between posts, their customers and other parties. The formal representation of postal products allows automated systems to efficiently consume new postal products as they are introduced by postal operators.
The current implementation of EPPML is based on XML technology, but the EPPML concepts may be implemented with other technologies (e.g.
relational database
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...
s,
semantic web). Each postal product is fully represented by one (and only one) postal product definition file (PPDF) which is an
XML document
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. ...
. A PPDF must be valid under the EPPML schema.
EPPML as a model of interaction
The 'M' in EPPML stands for Model. EPPML was defined by its authors as a model for the interaction between parties that create, publish, consume or deliver postal products.
The interactions defined by the model include actions on physical items, information exchanges and financial transactions. The typical action on a physical item is a change of location (e.g. delivery). The information exchanges may use either electronic channels (e.g.
web services, email) or physical channels (e.g.
bar codes
A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or o ...
printed on mail items by mailers and read posts). An example of a