field Registered
Verified 2026-09-18 · registry updated
2026-08-28If-Match
Makes a request conditional on the selected representation matching an entity tag.
Use If-Match with a strong ETag to protect writes from lost updates. A failed condition normally produces 412 Precondition Failed.
httpheaderconditionalconcurrency
Reference (http)
If-Match: "document-v7"
Use If-Match with a strong ETag to protect writes from lost updates. A failed condition normally produces 412 Precondition Failed.
Common mistakes
- Using a weak ETag for a byte-sensitive write precondition.
IANA registry: http-fields/field-names
Registry reference: RFC 9110, Section 13.1.1: HTTP Semantics