standards-compliance - Read For Learn

Can an HTML element have multiple ids?

No. From the XHTML 1.0 Spec In XML, fragment identifiers are of type ID, and there can only be a single attribute of type ID per element. Therefore, in XHTML 1.0 the id attribute is defined to be of type ID. In order to ensure that XHTML 1.0 documents are well-structured XML documents, XHTML 1.0 documents … Read more

Is it valid to have a html form inside another html form?

A. It is not valid HTML nor XHTML In the official W3C XHTML specification, Section B. “Element Prohibitions”, states that: http://www.w3.org/TR/xhtml1/#prohibitions As for the older HTML 3.2 spec, the section on the FORMS element states that: “Every form must be enclosed within a FORM element. There can be several forms in a single document, but the FORM … Read more