RFR: Clarifications and X-wnf label

[Jesper Wilhelmsson]

Fixed a bug, cleaned up a few JBS field references, and added the X-wnf label to the dictionary.

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Commit messages:
 - Clarifications and X-wnf label

Changes: https://git.openjdk.org/guide/pull/118/files
 Webrev: https://webrevs.openjdk.org/?repo=guide&pr=118&range=00
  Stats: 16 lines in 2 files changed: 10 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/guide/pull/118.diff
  Fetch: git fetch https://git.openjdk.org/guide.git pull/118/head:pull/118

PR: https://git.openjdk.org/guide/pull/118