Links and Webs - HTML and XHTML: The Definitive Guide - page 295

ftp://www.kumquat.com/planting/special/README.txt

Visually, the operation looks like that in Table 6-3 .

Table 6-3. Forming an absolute FTP URL

Protocol Server Directory File

Base URL http www.kumquat.com /planting guide.html

Relative URL ftp special README.txt

Absolute URLftp www.kumquat.com /planting/special README.txt

6.2.2.3. Using relative URLs

Relative URLs are more than just a typing convenience. Because they
are relative to the current server and directory, you can move an entire
set of documents to another directory or even another server and nev-
er have to change a single relative link. Imagine the difficulties if you
had to go into every source document and change the URL for every
link every time you moved it. You'd loathe using hyperlinks! Use relative
URLs wherever possible.