How is code *between* the end of the HEAD tag and before the BODY tag processed?

Question

I have read that it is bad to do this, and outside the spec, but I have an error that is somewhat intermittent, and may be related. Just want to know if the general consensus i

Answer 1

Fundamentally, it's invalid markup and a parsing error that the browser will have to recover from. So I would test this in your target browsers to see what they do.

In theory: After the closing tag and before the opening tag, the parser is in "'after head' insertion mode". I've listed the rules for that below, but thanks to your comment, I think the relevant one is:

• A start tag whose tag name is one of: "base", "basefont", "bgsound", "link", "meta", "noframes", "script", "style", "template", "title"
  • Parse error.
  • Push the node pointed to by the head element pointer onto the stack of open elements.
  • Process the token using the rules for the "in head" insertion mode.
  • Remove the node pointed to by the head element pointer from the stack of open elements. (It might not be the current node at this point.)
  • The head element pointer cannot be null at this point.

Which tells us that:

1. It's a parsing error, see my opening paragraph. :-)
2. The spec seems to be telling the browser vendors to treat the script as though it were at the end of the head.

The full rules:

When the user agent is to apply the rules for the "after head" insertion mode, the user agent must handle the token as follows:

• A character token that is one of U+0009 CHARACTER TABULATION, "LF" (U+000A), "FF" (U+000C), "CR" (U+000D), or U+0020 SPACE

  • Insert the character.

• A comment token

  • Insert a comment.

• A DOCTYPE token

  • Parse error. Ignore the token.

• A start tag whose tag name is "html"

  • Process the token using the rules for the "in body" insertion mode.

• A start tag whose tag name is "body"

  • Insert an HTML element for the token.
  • Set the frameset-ok flag to "not ok".
  • Switch the insertion mode to "in body".

• A start tag whose tag name is "frameset"

  • Insert an HTML element for the token.
  • Switch the insertion mode to "in frameset".

• A start tag whose tag name is one of: "base", "basefont", "bgsound", "link", "meta", "noframes", "script", "style", "template", "title"

  • Parse error.
  • Push the node pointed to by the head element pointer onto the stack of open elements.
  • Process the token using the rules for the "in head" insertion mode.
  • Remove the node pointed to by the head element pointer from the stack of open elements. (It might not be the current node at this point.)
  • The head element pointer cannot be null at this point.

• An end tag whose tag name is "template"

  • Process the token using the rules for the "in head" insertion mode.

• An end tag whose tag name is one of: "body", "html", "br"

  • Act as described in the "anything else" entry below.

• A start tag whose tag name is "head"

• Any other end tag

  • Parse error. Ignore the token.

• Anything else

  • Insert an HTML element for a "body" start tag token with no attributes.
  • Switch the insertion mode to "in body".
  • Reprocess the current token.