Well,


I got this message when I submitted this chunk,


<fixed><color><param>2222,6161,2F2F</param><bigger><x-tad-bigger><<blockquote></x-tad-bigger></bigger></color></fixed><fontfamily><param>Arial</param><bigger><x-tad-bigger>

   [The MD5 algorithm] takes as input a message of arbitrary length and

   produces 

   as output a 128-bit "fingerprint" or "message digest" of the input.

   It is conjectured that it is computationally infeasible to produce

   two messages having the same message digest, or to produce any

   message having a given prespecified target message digest. The MD5

   algorithm is intended for digital signature applications, where a

   large file must be "compressed" in a secure manner before being

   encrypted with a private (secret) key under a public-key
cryptosystem

   such as RSA.

</x-tad-bigger></bigger></fontfamily><fixed><color><param>2222,6161,2F2F</param><bigger><x-tad-bigger><</blockquote></x-tad-bigger></bigger></color></fixed><fontfamily><param>Arial</param><bigger><x-tad-bigger>


If character data cannot follow a block quote, what CAN?


If the text has to be wrapped inside the block quote with a <<p>
<</p>, why not say that?


Which is what appears to be needed.


with <<blockquote><<p> ... <</p><<blockquote> it seems to be happy. 
Why this "<<p><</p>" is necessary escapes me.


But a specific message should be more like:


A container tag was expected, you have text (character data)
</x-tad-bigger></bigger></fontfamily><italic>somewhere it is not
permitted to appear.  Mistakes that can cause this error include
putting text directly in the  body of the document without wrapping it
in a container element (such as  a <<p>aragraph<</p>) or forgetting to
quote an attribute value  (where characters such as "%" and "/" are
common, but cannot appear  without surrounding
quotes).</italic><fontfamily><param>Arial</param><bigger><x-tad-bigger> For
example: a <<blockquote> is not a container, and therefore the text
within should be in a container like <<p><</p> or <<div><</div>


Instead of:

</x-tad-bigger></bigger></fontfamily><bigger>	1.  	<italic>Line
<color><param>0000,0000,FFFF</param>83</color>, column 3</italic>:
<bold>character data is not allowed here


</bold></bigger><fontfamily><param>Courier</param><x-tad-smaller>  
</x-tad-smaller><bold><color><param>FFFF,0000,0000</param><x-tad-smaller>[</x-tad-smaller></color></bold><x-tad-smaller>The
MD5 algorithm] takes as input a message of arbitrary length and</x-tad-smaller><x-tad-smaller>


</x-tad-smaller></fontfamily><bold><italic><smaller>Help
Wanted!</smaller></italic></bold><italic><smaller> Can you think of a
better explanation for this  error message? Then please let us know by
sending a message to the
<color><param>0000,0000,FFFF</param>www-validator@w3.org</color> list
(be sure to quote the message number: #63).



</smaller></italic> <italic>You have used character data somewhere it
is not permitted to appear.  Mistakes that can cause this error
include putting text directly in the  body of the document without
wrapping it in a container element (such as  a <<p>aragraph<</p>) or
forgetting to quote an attribute value  (where characters such as "%"
and "/" are common, but cannot appear  without surrounding quotes).


</italic>Just as a side note, far too often we take the easy road and
do not have SPECIFIC error messages because so many are alike, so we
take the easy road and reuse error messages without being specific to
the EXACT error that occured.  In my case, the lack of the information
that a block quote is not a container, well, how am I supposed to know?