Which of the following is NOT typically contained within a span?

A span in distributed tracing is a fundamental concept used to represent a unit of work. It typically encapsulates several key pieces of information that facilitate the tracking and monitoring of processes within a distributed system.

The name of the span provides a descriptive identifier for the operation or task being carried out, allowing users to understand what service or method the span corresponds to.

Start and finish timestamps are essential as they provide the duration of the operation, which is critical for performance monitoring and identifying bottlenecks.

The parent span ID establishes the relationship between spans in a trace, indicating how different operations are connected in the execution path.

In contrast, source code is not part of what a span contains. While the source code of an application is relevant to understanding the functionality or performance of the operations being traced, it is not included in the span itself. The span focuses on metadata related to the operation's execution rather than the actual code that performs the work. This distinction is crucial for efficient tracing and monitoring within dynamic application environments.