A URL's path name component is sometimes case sensitive, depending on the web server's operating system. Although the domain name component is never case sensitive, the path name can be. For example, if the website is hosted on a Windows server:
www.bobsfruitsite.com/catalog/fruit.asp and
www.bobsfruitsite.com/CATALOG/Fruit.asp
are the same page, whereas on a UNIX server, they would be different pages.
A website built on a Windows server can therefore have URLs in both uppercase and lowercase, or a combination thereof, that refer to the same file presented to the browser. The web designer might not intentionally create links in mixed case, but the fact that a Windows web server permits these links without error means they inevitably happen.
Conversely, on UNIX servers, the above pages would be different. A mistake made by the web designer is not hidden; the page named with the wrong case would result in a 404 not found error.
At logfile processing time, ClickTracks needs to gather data for all unique pages. On a Windows server, the above requests are for the same page, so ClickTracks needs to know that the web server is not case sensitive.
Usually the case sensitivity of a web server is determined by the server's operating system. Windows and MacOS pre-OSX are not case sensitive. UNIX (including MacOSX and Linux) is case sensitive. The one exception to this rule concerns Apache, which can be configured with non-case-sensitive page names, even on a UNIX system. This situation is rare, however.
Unsure? Choose Not Case Sensitive
Not case sensitive is a safe choice because a site is very unlikely to contain both Index.html and index.htmlin the same directory. The effect of this setting is to convert all page file names to lowercase when "Not case sensitive" is chosen and to leave them as is for when "Case sensitive" is chosen. A Windows web server sees requests for Index.html and index.html as the same page, and yet they are recorded in the logfile as distinct pages. In this situation, ClickTracks needs to convert entries in the logfile into a single form, which it does by making everything lowercase. Case is preserved for UNIX servers because the page requested and the page logged are always the same, and Index.htmlmight be a different page than index.html.
