lay-url: URL link to a non-technical summary or review of the source; the URL title is set to "Lay summary". Aliases: lay-summary (deprecated), laysummary (deprecated).
lay-source: Name of the source of the laysummary. Displays in italics and preceded by an endash. Alias: laysource.
lay-date: Date of the summary. Displays in parentheses. Alias: laydate.