Where do public delivery specs disagree on forced narratives, textless elements and supplemental IMF packages (Netflix, Sky, Apple, SMPTE), and what does that imply for a multi-destination delivery?

Delivery platforms handle forced narrative (FN) subtitles and textless material in incompatible ways. Sky UK (spec dated Feb 2026) wants FN burnt into the picture and textless elements appended mute after the programme in the same file. In IMF, Sky refuses subtitle tracks (because 'Forced' tagging is used inconsistently), supplementary packages and OPLs. Netflix v5.2 forbids burned-in subtitled dialogue in the texted master, may request a separate textless IMF after approval, and takes supplemental IMPs for redeliveries. Apple's 2019 Compressor guide delivers forced subtitles as a separate .itt file. SMPTE ST 2067-2:2020 defines a ForcedNarrativeSequence and illustrates incomplete 'Version File' IMPs (in an informative annex), so a standard-conformant IMF package can still be refused by Sky. Curator qualifications: Specs read 2026-10-22; nothing packaged or delivered. Sky and Apple statements verified on producer copies (sky.pdf sha256 dd83e7b4dacdc6c3, equal to pin; apple-compressor.pdf sha256 8eee3f86c0ec63e1, equal to pin): Sky 3.3.3 'Sky does not currently support forced subtitles that are not burnt-in before delivery (including TTML in an IMF package)', 3.3.5 'Textless Elements must be included in the same deliverable, after the main feature/episode. These must also be mute', 6.15.4.11 'Subtitle tracks. This is due to inconsistent use of the “Forced” and non-forced tagging', 'Supplementary packages', 'Output Profile Lists (OPL)'; Apple 'Forced subtitles are delivered as a separate .itt file'. Netflix separate FN timed-text file carried from producer source S6 (not on the v5.2 page read). Curator amendment CA-AM-0054 (2026-10-22): Relation 'contradicts' (Sky IMF acceptance vs SMPTE ST 2067-2) is withdrawn and replaced by 'narrower_than'. ST 2067-2:2020 makes ForcedNarrativeSequence normative, but incomplete or supplemental IMPs appear only in informative text (7.1 Overview and Annex I). The standard does not oblige any destination to accept every conformant package, so Sky's refusal of subtitle tracks, supplementary packages and OPLs is a narrower delivery profile, not a contradiction of a normative rule. Read the accepted sentence 'a standard-conformant IMF package can still be refused by Sky' in that sense. This follows Amendment 11 (contradiction is kept for same-work or same-component conflicts). Limitations: Specs read 2026-10-22; nothing packaged or delivered. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

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      "note": "cited at https://web.archive.org/web/20260606051638id_/https://partnerhelp.netflixstudios.com/hc/en-us/articles/7262346654995-Post-Production-Branded-Delivery-Specifications; Netflix Post Production Branded Delivery Specifications v5.2 (Wayback 2026-06-06), sections 2.1-2.4; SMPTE ST 2067-2:2020 section 6.3.3 Table 14 and Annex I.2 (informative)"
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      "url": "https://pub.smpte.org/latest/st2067-2/st2067-2-2020.pdf",
      "note": "Netflix Post Production Branded Delivery Specifications v5.2 (Wayback 2026-06-06), sections 2.1-2.4; SMPTE ST 2067-2:2020 section 6.3.3 Table 14 and Annex I.2 (informative)"
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      "note": "Netflix Post Production Branded Delivery Specifications v5.2 (Wayback 2026-06-06), sections 2.1-2.4; SMPTE ST 2067-2:2020 section 6.3.3 Table 14 and Annex I.2 (informative)"
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      "note": "Netflix Post Production Branded Delivery Specifications v5.2 (Wayback 2026-06-06), sections 2.1-2.4; SMPTE ST 2067-2:2020 section 6.3.3 Table 14 and Annex I.2 (informative)"
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      "url": "https://web.archive.org/web/20260606051638id_/https://partnerhelp.netflixstudios.com/hc/en-us/articles/7262346654995-Post-Production-Branded-Delivery-Specifications",
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