Why is this an issue?

Hard-coding a URI makes it difficult to test a program for a variety of reasons:

In addition, hard-coded URIs can contain sensitive information, like IP addresses, and they should not be stored in the code.

For all those reasons, a URI should never be hard coded. Instead, it should be replaced by a customizable parameter.

Further, even if the elements of a URI are obtained dynamically, portability can still be limited if the path delimiters are hard-coded.

This rule raises an issue when URIs or path delimiters are hard-coded.