+ ['<code>/\b{}/</code>', 'boundary types: <em>gcb</em> (grapheme cluster), <em>sb</em> (sentence), <em>wb</em> (word)'],
+ ['<code>&.</code>', '<code>& | ^ ~</code> consistently numeric, dotted operators for strings', 'experimental::bitwise'],
+ [q"<code>use re 'strict'</code>", 'apply stricter syntax rules to regular expression patterns', 'experimental::re_strict'],
+ ['<code>0x.beep+0</code>', q"hexadecimal floating point notation with binary power; <code>printf '%a'</code> to display"],