Someone asked in the post on advanced search in Word, how you could search for "APLOMB" and change it to "aplomb" or "Aplomb".
The trick is to use the Match Case checkbox, like so:
If when you open search/replace you can't see these advanced options, then click the More button.
This example will match every instance of APLOMB in uppercase. (Notice it says Match Case in the line labelled Options). It will change to AplomB with a capital A and B, because that's what I wrote in the replace box.
This will work with any combination of upper and lower in the Find box. The replacement text will appear exactly as you write it in the replace box.
A much more useless but fun thing you can do is use search & replace to change the formatting of words. Here's an example.
Do the search/replace as before, but when you get to the replace dialogue, click the Format button and select Font (or anything else you like, but I'm using Font in the example).
This gives you the font formatting dialogue box. The example below searches for and replaces the word APLOMB, but not does not change the letters. It changes the font to 26 point, bold italic, comic sans in bright pink. Because, basically, I'm very weird.
The Effects section is very interesting. See all the effects options with filled in checkboxes? That means whatever the formatting currently is, leave it alone. That's the default and it does nothing.
If you click an effect checkbox once, it becomes a tick. That means change the formatting of whatever matches the search to include that effect. I've clicked Outline, so any word that matches will become an outline, as you can see in the preview.
If you click an effect checkbox a second time it completely blanks, which means turn off whatever the effect is. In the example I unchecked the Hidden effect, which means if any matching text had been hidden then it would have been revealed.
When you click OK on the font dialogue, and then click Replace All on the replace dialogue, it will turn every instance of APLOMB in your document into this large, pink, outlined abomination.
You can set virtually any formatting you like, if you can find it under the Format button.
I've never found a single practical use for this feature, but there you are, in case you can think of one.