docs/library/ure: Describe (lack of) escaping in character sets.
Only `\]` escape is supported.
@@ -17,7 +17,10 @@ Supported operators and special sequences are:
``[...]``
Match set of characters. Individual characters and ranges are supported,
- including negated sets (e.g. ``[^a-c]``).
+ including negated sets (e.g. ``[^a-c]``). To include ``]`` in the set,
+ it should be escaped, e.g.: ``r"[\]]"`` or ``"[\\]]"``. No other escapes
+ are supported (will lead to error). To include ``-`` in the set, it should
+ be listed as the first item, e.g. ``[^-0-9]``.
``^``
Match the start of the string.
