=item *
-Two hexadecimal numbers separated by a tabulator denoting a range
-of Unicode codepoints.
+Two hexadecimal numbers separated by horizontal whitespace (space or
+tabulator characters) denoting a range of Unicode codepoints to include.
=item *
-An existing character property prefixed by "+utf8::" to include
-all the characters in that property.
+Something to include, prefixed by "+": either an built-in character
+property (prefixed by "utf8::"), for all the characters in that
+property; or two hexadecimal codepoints for a range; or a single
+hexadecimal codepoint.
=item *
-An existing character property prefixed by "-utf8::" to exclude
-all the characters in that property.
+Something to exclude, prefixed by "-": either an existing character
+property (prefixed by "utf8::"), for all the characters in that
+property; or two hexadecimal codepoints for a range; or a single
+hexadecimal codepoint.
=item *
-An existing character property prefixed by "!utf8::" to include
-all except the characters in that property.
+Something to negate, prefixed "!": either an existing character
+property (prefixed by "utf8::") for all the characters except the
+characters in the property; or two hexadecimal codepoints for a range;
+or a single hexadecimal codepoint.
=back
UCS-2, UCS-4
Encodings defined by the ISO 10646 standard. UCS-2 is a 16-bit
-encoding, UCS-4 is a 32-bit encoding. Unlike UTF-16, UCS-2
-is not extensible beyond 0xFFFF, because it does not use surrogates.
+encoding. Unlike UTF-16, UCS-2 is not extensible beyond 0xFFFF,
+because it does not use surrogates. UCS-4 is a 32-bit encoding,
+functionally identical to UTF-32.
=item *