Connected with WebmasterWorld HTML forum:
Best to avoid having to URL encode a link in the first place. Is it OK to let the browser URL encode the link, or do we need to URL encode it for the benefit of older browsers? Blooberry.com mentions:
Internet Explorer is notoriously relaxed in its requirements for encoding spaces in URLs. This tends to contribute to author sloppiness in authoring URLs. Keep in mind that Netscape and Opera are much more strict on this point, and spaces MUST be encoded if the URL is to be considered to be correct.
[Link to a file with spaces in the name: "url_encoded filename with spaces.html"] - Does this work in all browsers?