Editing Case sensitivity (section)

==Areas of significance==
Case sensitivity may differ depending on the situation:

* [[String-searching algorithm|Searching]]: Users expect information retrieval systems to be able to have correct case sensitivity depending on the nature of an operation. Users looking for the word "dog" in an online journal probably do not wish to differentiate between "dog" or "Dog", as this is a writing distinction; the word should be matched whether it appears at the beginning of a sentence or not. On the other hand, users looking for information about a brand name, [[trademark]], human name, or city name may be interested in performing a case-sensitive operation to filter out irrelevant results. For example, somebody searching for the name "Jade" would not want to find references to the mineral called "jade". On the English Wikipedia, for example, a search for [[friendly fire]] returns the military article, but [[Friendly Fire (disambiguation)|Friendly Fire]] (capitalized "Fire") returns the disambiguation page.<ref group=NB>The link "Friendly Fire" must go through the (disambiguation) qualifier in a Wikipedia article to avoid a [[WP:INTDAB]] error.</ref><ref>See [[WP:DIFFCAPS]]</ref>
* [[Username]]s: Authentication systems usually treat usernames as case-insensitive to make them easier to remember, reducing typing complexity, and eliminate the possibility of both mistakes and [[Impersonator|fraud]] when two usernames are identical in every aspect except the case of one of their letters. However, these systems are not case-blind. They [[case preservation|preserve the case of the characters in the name]] so that users may choose an aesthetically pleasing username combination.
* [[Password]]s: Authentication systems usually treat passwords as case-sensitive. This enables the users to increase the complexity of their passwords.
* [[Filename#Letter case preservation|File names]]: Traditionally, [[Unix-like]] operating systems treat file names case-sensitively while [[Microsoft Windows]] is case-insensitive but, for most file systems, [[case preservation|case-preserving]]. For more details, see below.
* [[Variable (programming)|Variable names]]: Some programming languages are case-sensitive for their variable names while others are not. For more details, see below.
* [[URL]]s: The ''path'', ''query'', ''fragment'', and ''authority'' sections of a URL may or may not be case-sensitive, depending on the receiving [[web server]]. The ''scheme'' and ''host'' parts, however, are strictly lowercase.