1) Acvni 2) Admonisher 3) Cue 4) Letter 5) Memento 6) Memo 7) Note 8) Phylactery 9) Prompt 10) Souvenir 11) Tefillin 1) Content 2) Memory-jogger 3) Mental note 4) Message 5) Note on the fridge 6) Online calendar pop-up 7) Post-it Note 8) Posted Post-it note, often 9) Prompt 10) Souvenir 11) String around a finger 12) String around your finger 13) String on a finger 14) String on the finger 15) Subject matter 16) Substance 
• (n.) One who, or that which, reminds; that which serves to awaken remembrance.
Re·mind'er noun One who, or that which, reminds; that which serves to awaken remembrance. 
[n] - a message that helps you remember something 2. [n] - an experience that causes you to remember something
noun an experience that causes you to remember something