Craziest backslash escape?

• \1 (backreference)
• \101 (octal)
• \A
• \B
• \C
• \D
• \E
• \F (Update 2015-06-08: added, new in 5.16.0)
• \G
• \H
• \K
• \L
• \N{LATIN SMALL LETTER A}
• \N{latin:a}
• \N{U+2013} (Update 2010-11-24: added, newly documented in perl 5.12.0)
• \N (non-newline) (Update 2010-03-29: added, new in perl 5.12.0)
• \PL (Update 2008-08-29: added, dunno how I missed this)
• \P{IsLower} (Update 2008-08-29: added, dunno how I missed this)
• \Q
• \R
• \S
• \U
• \V
• \W
• \X
• \Z
• \a
• \b (backslash)
• \b (boundary)
• \cT
• \d
• \e
• \f
• \g1
• \g{-1}
• \g{named}
• \h
• \k<named> or \k{named} or \k'named'
• \l
• \n
• \o{20023} (Update 2010-11-24: added, new in perl 5.13.3)
• \pL
• \p{IsLower}
• \r
• \s
• \t
• \u
• \v
• \w
• \x41
• \x{2019}
• \z

We could also do favourite regex modifier, but that'd be too similar to I resolve to finally grok and use the regex option... except that we'd now also have /p. See also The most annoying common way to get a string literal in Perl is....