Adding AutoCorrect Exceptions

There is one AutoCorrect option that I like to always turn OFF in Excel: It is the "Correct TWo INitial CApitals" option.
As an engineer, I frequently work with units like MPa, where you DO want to use two initial capitals. It is very annoying to have "MPa" keep switching to "Mpa". To edit the AutoCorrect options:

• Excel 2003: Tools > AutoCorrect Options
• Excel 2010: File > Options > Proofing

Instead of turning off this option, you can add exceptions via the Exceptions button to the right of the autocorrect options. I'm embarrassed to say I've never noticed this button before today. That button opens up the AutoCorrect Exceptions dialog box which has an "INitial CAps" tab, where I can add my precious "MPa" exception. Yeah!