Described here:
http://old.nabble.com/Semantic-Forms%3A-Need-better-input-checking.-tt32128157.html
These characters cause problems on form inputs, and need to be rejected:
#<>[]|{}
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=34486
https://bugzilla.wikimedia.org/show_bug.cgi?id=34613