Ah, I see in `BidiBrackets-*.txt` the property values are `Open` and `Close`. `None` (`n`) is theoretically possible too.

```
+# Field 2: Bidi_Paired_Bracket_Type property value, one of the following:
 +#   o Open
 +#   c Close
 +#   n None
```

I’d prefer using the long-form names. What do you think?