I haven’t had my iPhone for that long, but a constant frustration is its overachieving autocorrection feature, which could use a bit of training on the peculiar words and acronyms I tend to use on a daily basis.
Our favorite iPhone hacker, Erica Sadun, recently investigated this very issue and found that not all text input areas measure up. Certain applications will update the iPhone’s custom word database, and some don’t appear to have any effect at all, namely Notes. Safari, however, seems to be the key to manually forcing a word into the database:
It wasn’t until I left Notes and hopped over to Mobile Safari that I was able to make any difference at all. In Mobile Safari, I opened a new browser, typed the same words into the Google search field and, in the words of Steve Jobs, boom. Just as one would hope, the dynamic-text.dat file immediately updated without any further repetition needed. I could also see the words by looking through the file.
To test my update, I then returned to Notes and tried typing my words again. This time, Notes immediately recognized my new additions as correct, without offering a special suggestion bubble.
If you’ve Jailbroken your phone and want an easier way to update the dictionary with your personal lingo, you can edit the file called dynamic-text.dat in /private/var/mobile/Library/Keyboard.