Phonetics and the IPA 6, Exercise 3: choosing diacritics

voiceless [n]   n̥  (voiceless ring below)   idea from Chapter 2: voicing
nasalised [z]   z̃  (tilde above)           idea from Chapter 2: velum lowered
syllabic [n]    n̩  (vertical mark below)   idea from Chapter 5: a vowel is the
                                           peak of a syllable; a syllabic
                                           consonant takes that role

Wikipedia gives n̥, z̃ and n̩ as its own examples, so these match the chart.