1. Index
  2. Encoding
  3. Commonality
  4. Missing
  5. Sandwich
  6. Tracking shape
  7. Cipher/cryptogram
  8. Absence
  9. Acrostic
  10. Middle initial
  11. Homophone
  12. Typeface/ font
  13. Repetition
  14. Abbreviations
  15. Mapping to alphabet
  16. Alignment
  17. Mapping word to word
  18. Intersection on grid
  19. Abecedary