HTM-000010 | Document Type Declaration
- The <!DOCTYPE html> declaration is used to inform a website visitor’s browser that the document being rendered is an HTML document. While not actually an HTML element itself, every HTML document should being with a DOCTYPE declaration to be compliant with HTML standards.When doing this even browsers that don’t presently support HTML5 to enter into standards mode, which means that they’ll interpret the long-established parts of HTML in an HTML5-compliant way while ignoring the new features of HTML5 they don’t support.This is much simpler than the former doctypes, and shorter, making it easier to remember and reducing the amount of bytes that must be downloaded.
- Things to Know
- The <!DOCTYPE> declaration is required to be the first thing in your HTML document and always precedes the <html> element.
- The <!DOCTYPE> declaration is an instruction to the web browser indicating what version of HTML the page is written in.
- In HTML 4.01, the <!DOCTYPE> declaration refers to a DTD, because HTML 4.01 was based on SGML. The DTD specifies the rules for the markup language, so that the browsers render the content correctly.
- HTML5 is not based on SGML, and therefore does not require a reference to a DTD.
- Common DOCTYPE Declarations
- HTML 5
- <!DOCTYPE html>
- HTML 4.01 Strict
- This DTD contains all HTML elements and attributes, but does NOT INCLUDE presentational or deprecated elements (like font). Framesets are not allowed.
- <!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01//EN” “http://www.w3.org/TR/html4/strict.dtd”>
- HTML 4.01 Transitional
- This DTD contains all HTML elements and attributes, INCLUDING presentational and deprecated elements (like font). Framesets are not allowed.
- <!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” “http://www.w3.org/TR/html4/loose.dtd”>
- HTML 4.01 Frameset
- This DTD is equal to HTML 4.01 Transitional, but allows the use of frameset content.
- <!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Frameset//EN” “http://www.w3.org/TR/html4/frameset.dtd”>
- XHTML 1.0 Strict
- This DTD contains all HTML elements and attributes, but does NOT INCLUDE presentational or deprecated elements (like font). Framesets are not allowed. The markup must also be written as well-formed XML.
- <!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd”>
- XHTML 1.0 Transitional
- This DTD contains all HTML elements and attributes, INCLUDING presentational and deprecated elements (like font). Framesets are not allowed. The markup must also be written as well-formed XML.
- <!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>
- XHTML 1.0 Frameset
- This DTD is equal to XHTML 1.0 Transitional, but allows the use of frameset content.
- <!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Frameset//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd”>
- XHTML 1.1
- This DTD is equal to XHTML 1.0 Strict, but allows you to add modules (for example to provide ruby support for East-Asian languages).
- <!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.1//EN” “http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd”>
- HTML 5
- Things to Know
<!DOCTYPE>
{post_title}
{post_content}
{associated_insight_resource.post_title}
{associated_insight_resource.resource_link}
{associated_insight_resource.insight_type }