System Preferences>Keyboard>Text. I use this to create trigger letter combinations that auto complete things I type frequently, particularly for business correspondence- for example if I type "FRA-", in any application, it prompts me with the option to autocomplete "For routing/assignment" I actually have someones difficult to spell's name in there too but have omitted it here. It"s useful to use ALL CAPS as the trigger. You can even stack the triggers, I have several individuals whom I may send a message to with "FOR ROUTING/ASSIGNMENT". to and I have them all triggered by the same capital letter combo, and I am presented with a dropdown list that use the down arrow to select which I want to use.