Recently I solved a problem with a POST request that failed with a 405 error (Method Not Allowed), even though there was only a POST endpoint at the requested URL. After solving the problem, I found it interesting enough to reproduce it and wrote a post about it.
HTTP protocol defines status codes as the means of informing the client about different error conditions on the server, but it can be beneficial to include additional information about the error. The best approach to it depends on the scenario.
In the world of connected applications programmatic HTTP requests are more and more common. In Windows Store applications HttpClient class serves most purposes as long as communication is targeted at services or at least the results are processed programmatically and don't need to be shown directly to the user.
The following code returns the time when a web resource was last modified. Maybe it will be useful to someone.