How to think about Shakespearean "Ciphers"

1. Three morals
2. Demonstrably valid ciphers
   • Hypnerotomachia Poliphili
   • Simple acrostics
   • Bacon's Biliteral cipher
   • Wilkins's Route transposition cipher
3. Failed "ciphers"
   • Accidental acrostics
     • Virgil's Aeneid
     • Milton's Paradise Lost
   • Penn Leary's Baconian "signatures"
     1. Was Longfellow Bacon?
   • B. M. Ward's Gascoigne string cipher
   • Rollett and the Sonnets
     1. Word acrostics
     2. Arrays and accidents