URL

Uniform Resource Locator

A URL is a URI that, "in addition to identifying a resource, provides a means of locating the resource by describing its primary access mechanism (e.g., its network location)".

http://en.wikipedia.org/wiki/Uniform_Resource_Locator

In theory "Cool URLs don't change". But that's never quite true.

• I try to save excerpts when I link-blog. I do this mainly to save re-reading time, and to crossref WikiWord-s, but I also do it so I can re-find a moved document years later.
• a 5-word Lexical Signature generated based on Tf Idf should be sufficient. (Like a Google Whack.)
• having your own Domain is a good risk-reducer

cf Url Shortener

Hyperlink provides a pure-Python implementation of immutable URLs. Based on RFC 3986 and RFC 3987, the Hyperlink URL balances simplicity and correctness for both URIs and IRIs.