SCTE 35 Part 1
sub_segment_num
segmentation_descriptor · Decimal
For the advertisement-start, placement-opportunity-start (including overlay), and ad-block-start types, numbers a sub-segment within a collection, one-based when sub-segment numbering is used and 0 when it is not. Present only for the segmentation types that use sub-segments.
Clause citations
Related and cross-protocol
Standards note
SCTE 35's sub-segment syntax condition lists specific segmentation types, while its usage guidance for promo, ad-block, and overlay placement types implies broader use; SCTE 35 2019 in particular has a syntax table and a usage table that disagree on the overlay types. We follow the syntax condition for decoding and flag the discrepancy.