The following sections describe miscellaneous user interface guidelines.
GUIDELINE: Avoid using titles longer than 24 characters for choice and entry cards.
When an UP.Phone displays a choice card, it automatically scrolls to the first choice on the card. Likewise, when it displays an entry card, it automatically scrolls to the entry field. This means that, if the title of a choice or entry card is too long to display on a single screen, the phone will scroll some of it off the top of the screen. The user will have to scroll back to read the entire title.
GUIDELINE: Use the NOECHO option to suppress display of secure information such as passwords.
The entry card provides a NOECHO option, which hides characters after the user enters them. Use this option to allow the user to enter secure information, such as passwords, in privacy.
Many sites require passwords containing mixed case and numbers. Therefore, it is recommended that you use the m format specifier. You may also want to make sure a password contains a minimum number of characters by using a specifier such as mmmmm*m, mmmmmm*m, or mmmmmmm*m.
For example, the HDML defines the password entry card displayed in Figure 8-10.
FIGURE 8-10. Password entry card
Note that the phone displays each character the user enters briefly, until the user begins to enter the next character. This enables the user to make sure he or she is entering the right characters.