Clause 4: Formatting abbreviations with sources

[ERyan71258]

We need to figure out a consistent way to format:

• A term with only an abbreviation. This would usually be listed in a separate "Abbreviations" clause or subclause, but can be included in the Terms and Definitions, with the appropriate heading, e.g., "Terms, Definitions, and Abbreviated Terms" Perhaps list as follows, all bold:

  Key Delivery Message KDM

• A term with only an abbreviation that cites a source. I would format as follows, with the term and its abbreviation in bold:

  Coordinated Universal Time UTC [SOURCE: ISO 8601-1]

[SteveLLamb]

Adding this comment to https://github.com/SMPTE/html-pub/issues/194 and closing here. This is a larger formatting issue.