No <head> tag needed....why?

velious · 10-17-2003, 01:36 AM

I am pretty good with HTML, and am currently teaching myself VBscript. I noticed in this example that the head and title tags were missing but yet i got the same effect...no problem occured.

<html>
<body>

<script type="text/vbscript">
document.write("Hello from VBScript!")
</script>

</body>
</html>

I know what the head tag is for, but if there is no code between the <head></head> tags, can it be left out, or is it good practice to include it anyway?

Spookster · 10-17-2003, 01:49 AM

You should always include it. The basic set of tags that should be in every web page should include:

PHP Code:


			


<html>

<head>

<title>My Webpage</title>

</head>

<body>

....

</body>

</html>

You should always include the title tag which goes in the head so you should always have a head. The title tag is the text that will show up on the title bar of the browser and will be what shows up as the text of the bookmark if someone bookmarks that page. If you do not put one then the person will have a blank bookmark.

liorean · 10-17-2003, 06:59 AM

Well, you may not leave it out. Html, head and body tags are required in an HTML document. It's just that the html, body and head opening tags are optional, so the browser should "fill them in" for you if they're absent.

Here's the smallest html document possible

Edit: well, unless you take into account the various SGML specials that browsers today don't support

:

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<title></title>
<p>

Which browsers - of course - SHOULD expand to the following

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
<title></title>
</head>
<body>
<p></p>
</body>
</html>

The problem is, not all browsers do that logic. So, you should never leave them out.

Spookster · 10-17-2003, 02:16 PM

I don't know if I would use the term optional. That's saying it is okay to leave them out.

Those tags are all apart of the structure of a web page. Unfortunately for some stupid reason these browser makers thought it would be a good idea to have their browsers try and correct mistakes in the web pages which of course is a very bad idea because if you do make a mistake then you are unlikely to catch it.

liorean · 10-17-2003, 03:19 PM

Well, optional is just the term the W3C uses. They are, according to the spec, required to be present but have optional start tags, so while they must be present in the document representation, they are not required in the actual document. As you can see in my minimal valid HTML 4.01 Strict document above.

This is not an effect of browser implementations, it's an effect of less-than-perfect SGML application engineering, by the IETF and later W3C.

Spookster · 10-17-2003, 05:17 PM

Quote:

Originally posted by liorean
Well, optional is just the term the W3C uses. They are, according to the spec, required to be present but have optional start tags, so while they must be present in the document representation, they are not required in the actual document. As you can see in my minimal valid HTML 4.01 Strict document above.

This is not an effect of browser implementations, it's an effect of less-than-perfect SGML application engineering, by the IETF and later W3C.

How can start tags be optional? Last time I checked if I didn't put in the starting tag of a set of HTML tag then it is not rendered properly or the browser attempts to correct it depending on the browser and which set of tags.

liorean · 10-17-2003, 06:23 PM

As I said, it's less-than-perfect engineering on part of those writing the standards. Have a look at the DTD if you don't believe me:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">

<!ELEMENT HTML O O (%html.content;) -- document root element -->
<!ELEMENT HEAD O O (%head.content;) +(%head.misc;) -- document head -->
<!ELEMENT TITLE - - (#PCDATA) -(%head.misc;) -- document title -->
<!ELEMENT BASE - O EMPTY -- document base URI -->
<!ELEMENT BODY O O (%block;|SCRIPT)+ +(INS|DEL) -- document body -->

<!ENTITY % html.content "HEAD, BODY">
<!ENTITY % head.content "TITLE & BASE?">

What you can read out of this is:
- The HTML element is required on behalf of being the root element specified in the doctype. It MUST contain one (and only one) HEAD element followed by one (and only one) BODY element, and nothing else. However, the part I've marked red also specifies that both start and end tag is optional.
- The HEAD element is thus required. Also here, however, start and end tags are both optional. It must contain one (and only one) TITLE element, in addition to one or zero BASE elements and any number of other HEAD content elements.
- The TITLE element may only contain parsed character data, no tags. As I've marked green here, it's start and end tags are required.
- The BASE element is included here only as comparison - this element is empty (may not contain anything) and as marked blue here, opening tag is required while end tag is optional.
- The BODY element, also required, has optional start and end tags too. It must contain one or more block or SCRIPT elements, and may contain INS and DEL elements.

Thus, a valid HTML document requires only the DOCTYPE, the TITLE and a block element. The user agent is REQUIRED to fill out the optional start and end tags for it's document representation. (which many browsers fail to do as they should)

Thus there exists a HTML, HEAD and BODY element even if the document doesn't explicitly specify them, because the browser should deduce where they should be from the other elements present in the document. That means you SHOULD be able to among other things style the body element even if it's not present in the actual document. Browsers, however, in their search to render everything thrown at them, very seldom do the correct deductions if they do them at all. Try the following for instance:

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<title>experiment</title>
<style type="text/css">
html{
    background-color: #ffa;
    color: #006;
    padding: 2em;
}

body{
    background-color: #aff;
    color: #600;
    padding: 2em;
}

p{
    background-color: #faf;
    color: #060;
    padding: 2em;
}
</style>
<p>paragraph

and have a look at how various browsers render it (especially if you change to transitional doctype instead <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">, to trigger quirks mode).

Spookster · 10-17-2003, 07:08 PM

Well if that is indeed true I think we should just ignore that and promote what should be the proper way of setting up the page using the minimum set of tags as posted earlier. I think discussing that would only aid in confusing newbies.

liorean · 10-17-2003, 07:52 PM

Well, I always promote the XML/XHTML way anyway...
I'd say you should recommend them a minimum document with a doctype though, and be sure to add the <meta content="text/html;charset=utf-8;" http-equiv="Content-Type" /> element directly following the opening head tag, just because.

giz · 10-17-2003, 08:00 PM

In order to make a valid document, you also need the Content-Type meta tag to state which character set the page uses (unless the server already sends it in the HTTP headers).

More on <head> structure in: http://www.codingforums.com/showthre...threadid=27444

Spookster · 10-17-2003, 08:02 PM

Quote:

Originally posted by Spookster
I think discussing that would only aid in confusing newbies.

I agree. Otherwise we end up with people asking "No <head> tag needed....why?"

liorean · 10-17-2003, 08:23 PM

Quote:

Originally posted by Spookster

Quote:

Originally posted by Spookster
[...]

I agree.

Talking to yourself, now ?

Spookster · 10-17-2003, 08:26 PM

lol

Yeah so. I don't think there are any forum rules against agreeing with yourself.

Spookster · 10-17-2003, 08:26 PM

Quote:

Originally posted by Spookster
lol Yeah so. I don't think there are any forum rules against agreeing with yourself.

I believe you are correct.

liorean · 10-17-2003, 08:29 PM

Quote:

Originally posted by Spookster
lol Yeah so. I don't think there are any forum rules against agreeing with yourself.

Well, it qould be seen as thread spamming if you do it too much, perhaps.

You know, they say talking to yourself is the first step towards insanity.

10-17-2003, 01:36 AM	PM User \| #1
velious Regular Coder Join Date: Jun 2003 Location: California Posts: 231 Thanks: 0 Thanked 0 Times in 0 Posts	No <head> tag needed....why? I am pretty good with HTML, and am currently teaching myself VBscript. I noticed in this example that the head and title tags were missing but yet i got the same effect...no problem occured. <html> <body> <script type="text/vbscript"> document.write("Hello from VBScript!") </script> </body> </html> I know what the head tag is for, but if there is no code between the <head></head> tags, can it be left out, or is it good practice to include it anyway?

10-17-2003, 01:49 AM	PM User \| #2
Spookster The Infractionator-inator Join Date: May 2002 Location: Marion, IA USA Posts: 5,605 Thanks: 3 Thanked 21 Times in 21 Posts	You should always include it. The basic set of tags that should be in every web page should include: PHP Code: `<html> <head> <title>My Webpage</title> </head> <body> .... </body> </html>` You should always include the title tag which goes in the head so you should always have a head. The title tag is the text that will show up on the title bar of the browser and will be what shows up as the text of the bookmark if someone bookmarks that page. If you do not put one then the person will have a blank bookmark. __________________ Spookster CodingForums Tyrant All Hail Spookster Where do you want to go today? Microso... errr Wrong!!! Make the switch Ubuntu Linux

10-17-2003, 06:59 AM	PM User \| #3
liorean The thread killer Join Date: Feb 2003 Location: Umeå, Sweden Posts: 5,575 Thanks: 0 Thanked 84 Times in 75 Posts	Well, you may not leave it out. Html, head and body tags are required in an HTML document. It's just that the html, body and head opening tags are optional, so the browser should "fill them in" for you if they're absent. Here's the smallest html document possible Edit: well, unless you take into account the various SGML specials that browsers today don't support : Code: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <title></title> <p> Which browsers - of course - SHOULD expand to the following Code: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <html> <head> <title></title> </head> <body> <p></p> </body> </html> The problem is, not all browsers do that logic. So, you should never leave them out. __________________ liorean <[lio@wg]> Articles: RegEx evolt wsabstract , Named Arguments Useful Threads: JavaScript Docs & Refs, FAQ - HTML & CSS Docs, FAQ - XML Doc & Refs Moz: JavaScript DOM Interfaces MSDN: JScript DHTML KDE: KJS KHTML Opera: Standards Last edited by liorean; 05-02-2004 at 10:37 PM..

10-17-2003, 02:16 PM	PM User \| #4
Spookster The Infractionator-inator Join Date: May 2002 Location: Marion, IA USA Posts: 5,605 Thanks: 3 Thanked 21 Times in 21 Posts	I don't know if I would use the term optional. That's saying it is okay to leave them out. Those tags are all apart of the structure of a web page. Unfortunately for some stupid reason these browser makers thought it would be a good idea to have their browsers try and correct mistakes in the web pages which of course is a very bad idea because if you do make a mistake then you are unlikely to catch it. __________________ Spookster CodingForums Tyrant All Hail Spookster Where do you want to go today? Microso... errr Wrong!!! Make the switch Ubuntu Linux

10-17-2003, 03:19 PM	PM User \| #5
liorean The thread killer Join Date: Feb 2003 Location: Umeå, Sweden Posts: 5,575 Thanks: 0 Thanked 84 Times in 75 Posts	Well, optional is just the term the W3C uses. They are, according to the spec, required to be present but have optional start tags, so while they must be present in the document representation, they are not required in the actual document. As you can see in my minimal valid HTML 4.01 Strict document above. This is not an effect of browser implementations, it's an effect of less-than-perfect SGML application engineering, by the IETF and later W3C. __________________ liorean <[lio@wg]> Articles: RegEx evolt wsabstract , Named Arguments Useful Threads: JavaScript Docs & Refs, FAQ - HTML & CSS Docs, FAQ - XML Doc & Refs Moz: JavaScript DOM Interfaces MSDN: JScript DHTML KDE: KJS KHTML Opera: Standards

10-17-2003, 06:23 PM	PM User \| #7
liorean The thread killer Join Date: Feb 2003 Location: Umeå, Sweden Posts: 5,575 Thanks: 0 Thanked 84 Times in 75 Posts	As I said, it's less-than-perfect engineering on part of those writing the standards. Have a look at the DTD if you don't believe me: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <!ELEMENT HTML O O (%html.content;) -- document root element --> <!ELEMENT HEAD O O (%head.content;) +(%head.misc;) -- document head --> <!ELEMENT TITLE - - (#PCDATA) -(%head.misc;) -- document title --> <!ELEMENT BASE - O EMPTY -- document base URI --> <!ELEMENT BODY O O (%block;\|SCRIPT)+ +(INS\|DEL) -- document body --> <!ENTITY % html.content "HEAD, BODY"> <!ENTITY % head.content "TITLE & BASE?"> What you can read out of this is: - The HTML element is required on behalf of being the root element specified in the doctype. It MUST contain one (and only one) HEAD element followed by one (and only one) BODY element, and nothing else. However, the part I've marked red also specifies that both start and end tag is optional. - The HEAD element is thus required. Also here, however, start and end tags are both optional. It must contain one (and only one) TITLE element, in addition to one or zero BASE elements and any number of other HEAD content elements. - The TITLE element may only contain parsed character data, no tags. As I've marked green here, it's start and end tags are required. - The BASE element is included here only as comparison - this element is empty (may not contain anything) and as marked blue here, opening tag is required while end tag is optional. - The BODY element, also required, has optional start and end tags too. It must contain one or more block or SCRIPT elements, and may contain INS and DEL elements. Thus, a valid HTML document requires only the DOCTYPE, the TITLE and a block element. The user agent is REQUIRED to fill out the optional start and end tags for it's document representation. (which many browsers fail to do as they should) Thus there exists a HTML, HEAD and BODY element even if the document doesn't explicitly specify them, because the browser should deduce where they should be from the other elements present in the document. That means you SHOULD be able to among other things style the body element even if it's not present in the actual document. Browsers, however, in their search to render everything thrown at them, very seldom do the correct deductions if they do them at all. Try the following for instance: Code: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <title>experiment</title> <style type="text/css"> html{ background-color: #ffa; color: #006; padding: 2em; } body{ background-color: #aff; color: #600; padding: 2em; } p{ background-color: #faf; color: #060; padding: 2em; } </style> <p>paragraph and have a look at how various browsers render it (especially if you change to transitional doctype instead <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">, to trigger quirks mode). __________________ liorean <[lio@wg]> Articles: RegEx evolt wsabstract , Named Arguments Useful Threads: JavaScript Docs & Refs, FAQ - HTML & CSS Docs, FAQ - XML Doc & Refs Moz: JavaScript DOM Interfaces MSDN: JScript DHTML KDE: KJS KHTML Opera: Standards Last edited by liorean; 10-17-2003 at 06:30 PM..

10-17-2003, 07:08 PM	PM User \| #8
Spookster The Infractionator-inator Join Date: May 2002 Location: Marion, IA USA Posts: 5,605 Thanks: 3 Thanked 21 Times in 21 Posts	Well if that is indeed true I think we should just ignore that and promote what should be the proper way of setting up the page using the minimum set of tags as posted earlier. I think discussing that would only aid in confusing newbies. __________________ Spookster CodingForums Tyrant All Hail Spookster Where do you want to go today? Microso... errr Wrong!!! Make the switch Ubuntu Linux

10-17-2003, 07:52 PM	PM User \| #9
liorean The thread killer Join Date: Feb 2003 Location: Umeå, Sweden Posts: 5,575 Thanks: 0 Thanked 84 Times in 75 Posts	Well, I always promote the XML/XHTML way anyway... I'd say you should recommend them a minimum document with a doctype though, and be sure to add the <meta content="text/html;charset=utf-8;" http-equiv="Content-Type" /> element directly following the opening head tag, just because. __________________ liorean <[lio@wg]> Articles: RegEx evolt wsabstract , Named Arguments Useful Threads: JavaScript Docs & Refs, FAQ - HTML & CSS Docs, FAQ - XML Doc & Refs Moz: JavaScript DOM Interfaces MSDN: JScript DHTML KDE: KJS KHTML Opera: Standards

10-17-2003, 08:00 PM	PM User \| #10
giz Regular Coder Join Date: Apr 2003 Location: UK Posts: 226 Thanks: 0 Thanked 0 Times in 0 Posts	In order to make a valid document, you also need the Content-Type meta tag to state which character set the page uses (unless the server already sends it in the HTTP headers). More on <head> structure in: http://www.codingforums.com/showthre...threadid=27444

10-17-2003, 08:26 PM	PM User \| #13
Spookster The Infractionator-inator Join Date: May 2002 Location: Marion, IA USA Posts: 5,605 Thanks: 3 Thanked 21 Times in 21 Posts	lol Yeah so. I don't think there are any forum rules against agreeing with yourself. __________________ Spookster CodingForums Tyrant All Hail Spookster Where do you want to go today? Microso... errr Wrong!!! Make the switch Ubuntu Linux

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