So, I had a UINavigationItem with a value for the “prompt” property (which shows the smaller text along the top of the bar).
I decided I didn’t like the text, so I removed it.
But the extra space remains.
Obviously I can just recreate this view… but I was wondering if anyone has seen this before, and if there is a simple fix (something akin to pressing ctrl-0 in SQL Management Studio to insert a null instead of an empty string).

For anyone interested, I just right-clicked on the .xib, and choose “Open As” > “Source Code”
Then I removed this line:
Problem solved.