Chapter 3: Advance HTML and XHTML Standards Flashcards

Vocabulary flashcards focusing on core concepts, syntax rules, semantic elements, and validator error types covered in Chapter 3.

XHTML

Extensible HyperText Markup Language, a stricter syntax variant of HTML that requires well-formed markup.

Well-formed Markup

Markup that follows strict syntax rules, such as requiring every element to be closed, proper element nesting, and exactly one root element wrapping the document.

Void Element

An element with no content or closing tag that must be self-closed with a trailing slash in XHTML, such as
, , , or

---

.

W3C Markup Validator

The official online tool (validator.w3.org) that inspects a document's code directly against the published specification, reporting specific line and column errors.

Root Element

The single outermost element in a document (such as ) that wraps all other content.

Conformance Error

A specific, named rule violation reported by a validator (such as an unclosed tag or unquoted attribute) tied to an exact line and column that keeps the document from passing validation.

Validator Warning

A message flagging something technically allowed but likely a mistake—such as a content-bearing image with an empty alt attribute—which does not block a passing result like an error does.

A semantic element representing one self-contained piece of content that makes sense on its own, syndicated elsewhere, and detached from the rest of the page.

A semantic element representing a distinct sub-topic within an article or page, ideally introduced by its own heading.

A semantic element representing content related to, but not central to, the main content—acting as a tangent rather than the primary point.

and

Semantic elements used together to pair an image with a genuine structural caption rather than relying on an unlinked nearby paragraph.

WCAG 2.2

Web Content Accessibility Guidelines 2.2; the W3C accessibility standard that evaluates whether assistive technology can identify page landmarks and navigate directly between them.

Nesting Order Rule

The XHTML rule requiring elements to close in the exact reverse order in which they were opened, preventing tags from crossing each other like an 'X'.

Duplicate id Value Error

A validator error occurring when the same id attribute value is assigned to more than one element in the same document, violating the rule that ids must be unique.

Element Not Allowed as Child Error

A structural validator error that occurs when an element is placed inside a parent element that prohibits it, such as placing a

tag directly inside a

instead of inside an
• .