Don't worry -- Word Substitution (aka AutoText) is still with us in BlackBerry 10. It's a bit harder to find now, and honestly, I looked for a while and then wrote it off as being a feature that went to the wind.
Thankfully it turned up and it's still hanging out in the settings waiting for your fancy strings of added words.
Word substitution is a great feature that lets you create auto text entries for common phrases. Use "ilu" for "I love you" or "omw" for "on my way".
You can put in pretty much anything you want. Take a stroll with us after the break and we'll see just how to get up and running with word substitution on BlackBerry 10.
Click Save and you're done. Repeat the process for adding as many words as you want.