<humour>A guy in the back alley. I give him the password "monk" and $20 and he spills the beans....</humour>

No - um, nowhere except in the documentation and the trials described above. The documentation says

The module can also export the %char2entity and the %entity2char hashes, which contain the mapping from all characters to the corresponding entities (and vice versa, respectively).

Which I took to mean "all characters that will be encoded by default". Then observed that encode_entities('@') does not encode @. So I wondered if that was because @ was not in the %char2entity hash, working on the assumption that %char2entity is the list of chars to encode by default. Using help from this board, I exported %char2entity and printed it out 

use HTML::Entities;
use HTML::Entities qw( %char2entity %entity2char ); #thanks ikegami

foreach $val (keys %char2entity) {
    print "<br>$val => $char2entity{$val}\n";
}

[download]
and found that @ IS in the %char2entity hash. Then trying your suggestion (assuming this is the same Anonymous Monk) of 
encode_entities($a, "\000-\377");

[download]
found that simply telling the module which characters to encode results in them being encoded, even though that command does not supply any new information about code-character mapping. The module, therefore, must already have that information, and it occurs to me that maybe that's the reason not all chars are encoded by default even though %char2entity contains a full set of char-entity relations - becase %char2entity is just a reference hash, NOT the list of chars to be encoded by deafult.

In reply to Re^3: HTML::Entities not encoding @ or . by punch_card_don
in thread HTML::Entities not encoding @ or . by punch_card_don

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.