t.</b> Strings being arbitrary sequences of bytes, they
    can hold any kind of textual encoding. However the recommended
    encoding for storing Unicode text in OCaml strings is UTF-8. This
    is the encoding used by Unicode escapes in string literals. For
    example the string <code class="code"><span class="string">"\u{1F42B}"</span></code> is the UTF-8 encoding of the
    Unicode character U+1F42B.</p>

<p><b>Past mutability.</b> Before OCaml 4.02, strings used to be modifiable in
    place like <a 