Editing User-Agent header (section)

=== Encryption strength notations ===

Web browsers created in the United States, such as [[Netscape Navigator]] and [[Internet Explorer]], previously used the letters U, I, and N to specify the [[encryption]] strength in the user agent string. Until 1996, when the United States government allowed encryption with keys longer than 40 bits to be exported, vendors shipped various browser versions with different encryption strengths. "U" stands for "USA" (for the version with 128-bit encryption), "I" stands for "International"{{snd}} the browser has 40-bit encryption and can be used anywhere in the world{{snd}} and "N" stands (''de facto'') for "None" (no encryption).<ref name=zawinski-old>{{cite web
| url = https://www-archive.mozilla.org/build/user-agent-strings.html
| title = user-agent strings (obsolete)
| first = Jamie
| last = Zawinski
| date = 28 March 1998
| access-date = 2010-01-08
| publisher = mozilla.org
}}</ref> Following the lifting of [[export of cryptography in the United States#PC era|export restrictions]], most vendors supported 256-bit encryption.