How about validating the input?

This is a very small tweak: the instructions for creating a path alias are too technical.

The advice which appears onscreen in v4.5.2 says

Specify an alternative path by which this data can be accessed. Use a relative path and don't add a trailing slash or the URL alias won't work.

(emphasis added)

But the secind sentence will be confusing for non-technical users: most users don't know what a relative path is.

I suggest a better wording would be

Specify an alternative path by which this data can be accessed. Use a relative path, i.e. one which does not begin with a slash. Don't start with a slash and don't add a trailing slash, or the URL alias won't work.

At the risk of making it all too verbose, it would be nice to add a few examples:

Specify an alternative path by which this data can be accessed. Use a relative path, i.e. one which does not begin with a slash. Don't start with a slash and don't add a trailing slash, or the URL alias won't work (e.g. "help" is fine, but these are wrong:"/help", "/help/" or "help/")

The text appears twice in path.module: in function path_form() and function path_nodeapi(), at lines 178 and 211 respectively