Alphanumeric Code Characters


  • When generating alphanumeric codes that a user may need to enter or reference, there are certain characters that should be avoided to prevent usability issues.

Design Guidelines#

Use when#

  • A code or reference ID is being generated by the system.

Usable Characters#

  • Letters
  • Numbers
  • Symbols

Unusable Letters#

  • I O S

Letters to avoid unless additional characters are necessary#

  • U V

Unusable Numbers#

  • 0 1 2 5


  • Display letters in ALL CAPS
Last updated on by Paulo Andrade