What do YouTube's playlist and Posts (community post) help pages document that matters for series packaging and audience contact, and what do they not say about session watch time?

Problem: planning a series playlist and companion posts. Conditions: desktop YouTube and Studio. Method (documented): playlists can hold videos and Shorts; creators can reorder them by dragging (not for Shorts-only playlists), filter by All/Shorts/Videos, and there is a daily limit on public playlists a channel can create, raised by advanced features. Deleting a playlist removes its URL and title from Analytics and stops attributing watch time to it, though the watch time stays in broader reports. Posts can be text, image/GIF (up to 10 images, JPG/PNG/GIF/WEBP, up to 16 MB, a suggested 1:1 ratio because that is how the feed shows them), video, poll, quiz or playlist posts; they can be scheduled; mentions with @ may notify the channel; a post sharing another creator's video may notify them; a posts-per-24-hours limit applies; and a post about a video already in a viewer's feed might not show again. Failure modes: expecting analytics for a playlist after deleting it; sharing a viewer's already-seen video in a post. Limitations: neither page says playlists or posts raise session watch time or reach beyond a general line that posts 'can give you more reach'; any such effect is therefore unevidenced here. Version/date: help pages read 2026-10-23. Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Documentation is procedural; the 'more reach' phrase is a platform claim without data on these pages. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://support.google.com/youtube/answer/57792?hl=en",
      "note": "Delete a playlist; Create a playlist; Image and GIF posts; Create a post"
    },
    {
      "url": "https://support.google.com/youtube/answer/7124474?hl=en",
      "note": "Delete a playlist; Create a playlist; Image and GIF posts; Create a post"
    }
  ]
}