That is the correct behavior, your conclusion "=for comment hides text from perl but not perldoc" isn't correct. From perlpod (emphasis mine):
The command "=for formatname text..." specifies that the remainder of just this paragraph (starting right after formatname) is in that special format.
Remove the blank line after the =for and the "Comment!" is hidden. The =for still begins a section of POD that needs to be terminated by =cut, so Perl will ignore the entire example you posted.
Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
Want more info? How to link or
or How to display code and escape characters
are good places to start.