A standard Blogger blog, by default, provides a terse advice, for invalid URLs.
Sorry, the page you were looking for in this blog does not exist.Would it not be more user friendly, to use relevant slang, maybe.
Sorry, bro - that's not on!You can do this - and more - with a little imagination.
Blogger gives us a Custom "404 Not Found" display, similar to the customisable comment form message.
Using the "Custom Page Not Found" wizard at Settings - Search preferences - Errors and redirections, you just click on "Edit", and add simple text.
Sorry, bro - that's not on!That's slightly more interesting, than the default.
The default is boring - and confusing.
Boring - and slightly confusing. Why do I care about "pages"?
How about some bling?
Make the message more relevant, easily enough.
You can see this tweak, live, in my test blog.
A bit of simple HTML, and you can have something somewhat shinier.
With slightly more effort, we can have something much more interesting.
<img border="0" src="http://2.bp.blogspot.com/-PA3CmDhS3sw/VKd-o-zt1iI/AAAAAAAAOWE/WpdHLS3TFI4/s400/404%5B4%5D.png" /><br clear=all />Sorry, bro - that's not on!<br /><br />Try the <a href="http://blogging.nitecruzr.net/p/topics.html">Topic Index</a>, instead.You can see this tweak, live, in this blog.
Now, we're getting somewhere!
It all depends upon the limits in your imagination - or your ability to use Google Search. This example, here, may be a bit off the wall.
If you think about it, a custom 404 page is a good complement to a "Welcome" post, in a stub blog. You can link to an index of the posts, in the new blog, for instance. Similarly, if you migrate a non Google domain, into a Blogger blog.