Treat a URL as a publishing promise
For an owned package, decide whether a segment URL identifies stable bytes or a mutable slot. Both naming approaches need policy, but they should not accidentally share contradictory cache assumptions. A resource advertised as stable should not quietly change during its intended cache lifetime.
RFC 8246's immutable extension concerns resources that will not change during their freshness lifetime. It is not a command that makes an overwritten resource coherent across caches. Establish the stability promise before using the directive.
Keep a release ledger
For an invented correction from generation R1 to R2, record the changed segment identities, initialisation references and manifest revision. If only the subtitle sidecar changes, identify that change separately instead of making every resource look new without a reason.
A digest-based name or a controlled generation directory can make the relationship explicit. Choose the method that the publishing system can maintain reliably. The example does not require a particular hash algorithm or storage vendor.
Make rollback a real operation
Retain the previous manifest and resources for the planned rollback and active-reader interval. Rolling back only the manifest is ineffective if its referenced media has already been removed. Conversely, retaining files without knowing their release membership makes cleanup difficult.
Check the normal delivery route after publication and keep the observed identities. A local directory comparison cannot establish what an intermediary serves. This article describes a release strategy, not a measured cache hit rate or an IPTV Europe deployment change.
Questions answered
Does immutable mean a file can never be deleted?
No. It expresses a freshness-period stability promise; retention needs a separate publication policy.
Must every revised package rename every unchanged segment?
No. Keep identity tied to the bytes and the release design rather than renaming without a purpose.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.