$notifywindows()

• This function returns a space-separated list of window refnums that meet the following criteria:
• The window must have /window notify ON
• The window must be hidden
• The window must have received output since it was hidden
• If no windows meet this criteria, the empty string is returned.

This is essentially the same information that the %F status line expando returns.

The list of “notify-on-output-when-hidden” windows that have had output since they were hidden.