What is the significance of trailing slashes in a namespace URI?

Question

I have been studying SOAP and WSDL in preparation for implementing a web service. One thing that I have encountered that puzzles me is that some of the URIs that I have seen use a trailing slash such as:

http://www.w3.org/some-namespace/

while other examples that I have studied omit this trailing slash. I really have several questions regarding this:

• What is the significance of the trailing slash?
• Is the URI, http://www.w3.org/some-namespace the same as http://www.w3.org/some-namespace/?
• If they are not the same, how do I decide when one form is warranted versus another?
• I have read the guidelines given by w3c regarding URI's and these appear to indicate that that URI should be considered equal only if the case-sensitive comparison of the URI strings are considered equal. Is this interpretation correct?

Answer 1

Yes, the w3c guidelines regarding URI's you have read are correct.

The two namespaces having not equal-strings-uri's are different namespaces. Even capitalization and white-space matters.

A namespace-uri does not mean that issuing a request for it should produce a web-response. Therefore, any reasoning whether it should or shouldn't end with "/" is not too meaningful.

In fact, a namespace-uri may even not satisfy the syntax rules for an URI and it will still serve its purpose for defining a namespace. It is perfectly useful to use a namespace such as, let's say:

"\/^%$#sdhfgds"

as long as it is unique (do note that in no way I am recommending such use :) ). Existing XML processors (such as parsers, XPath or XSLT processors) do not raise any errors when they encounter such namespace.