https://phpxref.ftwr.co.uk/buddypress/_functions/mark_as_unread.html
PHPXRef 0.7.1 : BuddyPress : Function Reference: mark_as_unread()
function referencebuddypressmarkunread
https://www.markvapps.com/proaudioconverter/help/format-specifiers
Pro Audio Converter Format Specifiers Reference | Mark V Apps
Complete reference of format specifiers available in Pro Audio Converter for custom output file names, folder structures, and iTunes playlist names.
pro audioreference markconverterformatspecifiers
https://lilypond.org/doc/v2.25/Documentation/internals/segno_002dmark_002dinterface
3.2.128 segno-mark-interface (LilyPond Internals Reference)
3.2.128 segno-mark-interface (LilyPond Internals Reference)
segnomarkinterfacelilypondinternals