Custom 404 Error Page

[globay]

Does Google or a Browser notice, if it is presented a custom 404 error page <and not an other site>?

Is there some information sent, that the page could not be found,
when using:

.htaccess
ErrorDocument 404 /errors/404.html

Thanks

--
globay

if yes, how can I prevent that?

[grahamstewart]

Yeah, there should be a 404 status code sent to the browser/bot as well as the html.

Don't know if you could block that - but you might be able to replace it by using the header() function on the php page - not sure..

What is it your trying to do?

[globay]

I could use it for something like this:

On a partly dynamic site: if the folder/page could not be found, then the folders and the file name are parsed and used to draw some unique content from the database.

[globay]

I am not sure about the header() function. It will replace a 404 Error that was already sent with a 200. It should work fine for IE etc, but what does Google think, if there's first a 404 and then a 200?