Strength of Evidence:
Document Type: Guideline
Controls and Widgets
Treat upper- and lowercase letters as equivalent when users are entering codes.
Do not make user-entered codes case sensitive unless there is a valid reason for doing so (such as increased security of passwords). If required, clearly inform users if they must enter codes in a case specific manner. When retaining data entered by users, show the data as it was entered by the user.
Related Usability Guidelines: