```yaml
version: "1.0"          # increment on meaningful changes to the skill
updated: YYYY-MM-DD     # ISO date of last update

# when: describes when this skill is loaded — the full trigger context.
# More detail than the description field; not used for routing.
when: <describe the invocation conditions here>

# source: tracks content you ADOPTED from an upstream repo.
# Adopt = you read someone else's code or docs and incorporated text or logic directly.
# Omit this field entirely if the skill is self-authored — absence means original work.
# Present only when content was actually taken, tracked at commit-level for upgrade reviews.
source:
  - repo: org/repo-name          # GitHub slug — no URL, slug is stable and searchable
    commit: <full SHA>           # exact commit reviewed at time of adoption
    files:
      - path/to/file.md          # inline comment: what was taken from this file
      - path/to/other.md         # inline comment: what was taken from this file
    updated: YYYY-MM-DD          # date this source entry was last reviewed

# references: tracks content you CITED but did not adopt verbatim.
# Cite = you read it and it informed the skill, but nothing was copied or adapted.
# Examples: a spec you followed, a paper that shaped the approach, external documentation.
# Distinct from source: source = took content; references = informed by content.
references:
  - https://example.com/relevant-doc
```