The best replacement for letters is numbers.

The best alternatives to letters are rated as following:
★★★★★  numbers
★★  email
★★  memos
★★  recommendation
★  resignation
★  reference
★  poems
★  emails
★  lowercase
★  postcards
★  flats
  symbols
  business letters
  informal letters
  texting
  personal letters
  letters
  phonemes
  writing emails
  notes
  numbers on phone
  e-mail
  small letters

Your alternative for letters is not listed? Suggest!
Speaking about letters, one probably shouldn't forget about accents.

Other search terms related to letters and their ratings are:
★★★★★ accents
★★★ rotational symmetry
★★ enclosures
★ prejudice examples
★ name
★ postcode
★ symbols
★ zip codes
★ cutters
★ accent
★ words
resumes
q and no u
numbers
symmetry
fault
You have in mind a companion for letters and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of letters in all years. Click on graph for more.
letters
numbers
email