PRODID

PRODID is a property defined by the iCalendar specification (RFC 5545) used to identify the product or application that created an iCalendar object. It is a characteristic of the VCALENDAR component and is typically included to indicate the origin of the calendar data. The property helps recipients and calendar applications distinguish calendars from different sources and troubleshoot compatibility or provenance issues.

The value of PRODID is a free-form text string. While the exact syntax is not strictly enforced, the convention is to format it as a globally unique identifier for the producing product, often following a structured form such as -//Organization//Product//Version or a simple name plus version, with an optional language tag. Examples include -//ExampleCo//EventMaker//EN or ExampleCo EventMaker 3.4. The key goal is to provide a stable, recognizable identifier for the calendar-producing software or organization.

Rationale and usage: PRODID enables calendar clients to recognize the origin of a calendar file, aids in version and compatibility checks, and supports data management when calendars are created, exported, or merged across different applications. It is intended to be stable across edits and exports, helping to trace back to the producing product.

Standards notes: According to RFC 5545, the PRODID property should be present in VCALENDAR data and should serve as a clear, unique identifier for the producing product. It is not a security token and should not be relied upon for authentication or trust verification.