Tooltip / screenreader feedback for "space" on Special Characters palette is noteLongaSquareDown
1) edit some text
2) press F2 to display Special Characters palette
3) hover mouse over the "space" just before the copyright symbol
Result: tooltip says "noteLongaSquareDown".
I am pretty sure this is because the symNames and symUserNames arrays got out of sync. My guess is it involves the ornamentDownPrall ("Down prall") which appears to have moved a couple of times and current has an entry in symUserNames (towards the very very end of the list) but is commented out in symNames.
An easy enough for someone who understands where this symbol does belong, but that's not me.