Style sheet languages may be used to control the formatting and presentation of structured documents, such as documents written in markup languages like Hyper Text Markup Language (“HTML”) and Extensible Markup Language (“XML”). Using style sheet languages, the contents of a document, which may be included in an HTML or XML computer file, thus may be defined and stored independently of the formatting of the document, which may be stored in a style sheet computer file.
Today, Cascading Style Sheets (“CSS”) is a popular style sheet language by which one or more style parameters of a structured document, such as a webpage, may be controlled and/or modified. For example, using CSS, a webpage developer may control the background color or image of a webpage; the spacing and location of paragraphs and other body elements like images and tables; and the color, size, and face of fonts used in the webpage. CSS includes a plurality of commands for controlling and/or modifying such parameters, including, for example, the @font-face command.
In the past, when the @font-face command was yet to be supported by many web browsing computer programs, a website developer may have been limited in selecting one or more fonts to be used in a webpage because the website developer may have had to account for the possibility that at least one of the selected fonts might not be installed on the computer of a user who later might access the webpage. In the present, however, by using the @font-face command in the CSS code of a webpage, a website developer may link to a font stored elsewhere on the Internet, such that when a user accesses the webpage, the user's computer may display the webpage using the linked font even though the linked font might not be installed on the user's computer in advance of accessing the webpage.
While the @font-face command may be used in providing such functionality, a website developer further may wish to allow only certain, authorized servers and/or websites to access linkable fonts maintained online by the website developer. In some instances, it may be desirable to limit access to linkable fonts because a website developer may wish to control the amount of bandwidth used in providing linkable fonts. In other instances, it may be desirable to limit access to linkable fonts because a website developer's use of linkable fonts may be subject to license restrictions, and the website developer may be required to limit access to linkable fonts by the terms of such license restrictions.