Guideline E: Input and output interfaces

E5: Implementing capital lock function



Implementing capital lock function

The Capital Lock function converts alphabetic characters to their uppercase equivalents. Since each script has its own rules for changing lowercase characters into uppercase, the Capital Lock function must respect these differences.


Guideline E5


Design the keyboard Capital Lock function that considers the active national language.


When Capital Lock is on, the output from a key must not be tied to the character content of other levels of the same key. On many keyboards, both levels 1 and 2 of a key can contain unique lowercase characters.

Example: Italian keyboards make double use of certain keys. For example, the same key will display the ò character on level 1 and the ç character on level 2 in the IBM Italian keyboard 142 (PDF, 82KB).