iOS 4 User Dictionary: Not What it Seems
Something that I’ve not seen mentioned accurately in any reviews is the appearance of an “Edit User Dictionary” option in the Keyboard Settings. It appears if a Japanese or Chinese – Pinyin keyboard is selected.
Many people, seeing it, have assumed that it is a way to add words to the auto-correction or spelling dictionary. It is not.
The user dictionary is designed to help people writing Japanese or Chinese. It allows users to pre-set which Chinese characters appear when they type a phonetic version of a word. It’s commonly used for names of places and people and is a standard feature of most character based input systems and, as such, is a very welcome addition to iOS.
Entering words in here will neither add them to the auto-correct dictionary, stop them from being underlined in red or enable any Text Expander like features.