PID stands for Packet Identifier. The SCTE 35 PID entry is shown only if SCTE 104 AD Insertion Triggers are enabled.

SCTE-35 Example Source Code

• Comcast go MPEG transport streams library
• Comcast JS scte-35 parser
• SCTE 35 Encoder/Decoder in Java

• Implements the SCTE-35 standard in Type Script for representing digital program insertion cues.

• threefive: scte-35 parser for mpegts, hls, and encoded strings
• ffmpeg with scte 35 implementation

The only Apple supported way of including SCTE-35 data is via the EXT-X-DATERANGE tag with the various SCTE35 attributes.

See the spec for the details - https://tools.ietf.org/html/draft-pantos-http-live-streaming

See also the WWDC 2016 video - What's New in HTTP Live Streaming - https://developer.apple.com/videos/play/wwdc2016/504/ which talks about the various ways metadata can be included in HLS streams.