The OSDM specification is structured into two parts sharing common data structures:
Common Data Structures
The Common Data Structures are shared between the Offline Model and the Online API. Here, of special interest is the relationships between offers, offerparts, products and fares.
Part I: Offline Model
The Offline Model defines how the offline data can be exchanged.
Part II: Online API
The OnlineAPI is explained in these documents:
Catalog of Code Lists
A Catalog of Code Lists defines attributes and provides references to standards used.
Compliance to the Specification
In order for an implementation to be compliant, depending on its role, a set of service need to be implemented as lined out in the Compliance section.
Availability as UIC Leaflet
The specification is also available as IRS-90918-10 Leaflet.