Editing HTML (section)

== Delivery ==
HTML documents can be delivered by the same means as any other computer file. However, they are most often delivered either by [[Hypertext Transfer Protocol|HTTP]] from a [[web server]] or by [[email]].

=== HTTP ===
{{Main|Hypertext Transfer Protocol}}
The [[World Wide Web]] is composed primarily of HTML documents transmitted from web servers to web browsers using the [[Hypertext Transfer Protocol]] (HTTP). However, HTTP is used to serve images, sound, and other content, in addition to HTML. To allow the web browser to know how to handle each document it receives, other information is transmitted along with the document. This [[meta data]] usually includes the [[MIME type]] (e.g., <kbd>text/html</kbd> or <kbd>application/xhtml+xml</kbd>) and the character encoding (see [[Character encodings in HTML]]).

In modern browsers, the MIME type that is sent with the HTML document may affect how the document is initially interpreted. A document sent with the XHTML MIME type is expected to be [[Well-formed document|well-formed]] XML; syntax errors may cause the browser to fail to render it. The same document sent with the HTML MIME type might be displayed successfully since some browsers are more lenient with HTML.

The W3C recommendations state that XHTML 1.0 documents that follow guidelines set forth in the recommendation's Appendix C may be labeled with either MIME Type.<ref>{{cite web|url=https://www.w3.org/TR/xhtml1/#media|title=XHTML 1.0 The Extensible HyperText Markup Language (Second Edition)|publisher=World Wide Web Consortium|orig-date=2000|year=2002|access-date=December 7, 2008|quote=XHTML Documents which follow the guidelines set forth in Appendix C, "HTML Compatibility Guidelines" may be labeled with the Internet Media Type "text/html" [RFC2854], as they are compatible with most HTML browsers. Those documents, and any other document conforming to this specification, may also be labeled with the Internet Media Type "application/xhtml+xml" as defined in [RFC3236].}}</ref> XHTML 1.1 also states that XHTML 1.1 documents should{{Ref RFC|2119|quote=3. SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course. }} be labeled with either MIME type.<ref>{{cite web|url=https://www.w3.org/TR/xhtml11/conformance.html#strict|title=XHTML 1.1 – Module-based XHTML&nbsp;— Second Edition|publisher=World Wide Web Consortium|year=2007|access-date=December 7, 2008|quote=XHTML 1.1 documents SHOULD be labeled with the Internet Media Type text/html as defined in [RFC2854] or application/xhtml+xml as defined in [RFC3236].}}</ref>

=== HTML e-mail ===
{{Main|HTML email}}
Most graphical email clients allow the use of a subset of HTML (often ill-defined) to provide formatting and [[semantic web|semantic]] markup not available with [[plain text]]. This may include typographic information like colored headings, emphasized and quoted text, inline images and diagrams. Many such clients include both a [[Graphical user interface|GUI]] editor for composing HTML e-mail messages and a rendering engine for displaying them. Use of HTML in e-mail is criticized by some because of compatibility issues, because it can help disguise [[phishing]] attacks, because of accessibility issues for blind or visually impaired people, because it can confuse [[Email spam|spam]] filters and because the message size is larger than plain text.

=== Naming conventions ===
The most common [[filename extension]] for [[computer file|files]] containing HTML is <kbd>.html</kbd>. A common abbreviation of this is <kbd>.htm</kbd>, which originated because some early operating systems and file systems, such as [[DOS]] and the limitations imposed by [[File Allocation Table|FAT]] data structure, limited file extensions to [[8.3 filename|three letters]].<ref>{{cite web|title=Naming Files, Paths, and Namespaces|url=https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396|publisher=Microsoft|access-date=16 March 2015}}</ref>

=== HTML Application ===
{{Main|HTML Application}}
An HTML Application (HTA; file extension <kbd>.hta</kbd>) is a [[Microsoft Windows]] application that uses HTML and Dynamic HTML in a [[Web browser|browser]] to provide the application's graphical interface. A regular HTML file is confined to the security model of the [[Browser security|web browser's security]], communicating only to web servers and manipulating only web page objects and [[HTTP cookie|site cookies]]. An HTA runs as a fully trusted application and therefore has more privileges, like creation/editing/removal of files and [[Windows Registry]] entries. Because they operate outside the browser's security model, HTAs cannot be executed via HTTP, but must be downloaded (just like an [[EXE]] file) and executed from local file system.