A brief analysis of HTML file HEAD internal tags

Today, it is very easy to create a homepage using various WYSIWYG tools. However, understanding the HTML source code and syntax will undoubtedly be of greater help to us in making the homepage, and also enable users to control the effect of the page more accurately. There are many articles introducing HTML syntax, but in addition to the TITLE tag, there are several other tags in HEAD. Although these marks are not commonly used, we need to have a certain understanding of them.
1. META
META tag is used to describe some document information that is not included in standard HTML. Fierce competition has led browser manufacturers to use META to develop many practical functions, and make these functions effective in commonly used browsers. Here are some very useful usages:
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Keywords for this page and description. After adding these definitions to the page, some search engines can allow readers to find your homepage based on these keywords and understand the content of your homepage.
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The browser will automatically redirect to new.htm after 60 seconds. You can use this function to create a The cover will automatically bring readers to your directory page after a certain amount of time.
If the URL item is not available, the browser will refresh this page. This implements the feature of regular refresh of the WWW chat room
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Describe the language used on this page. Based on this item, the browser can select the correct language encoding without the need for the reader to enter it in the browser. Select. GB2312 refers to Simplified Chinese, and the homepage of Taiwan's BIG5 internal code uses BIG5.
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Mandatory call to the latest version on the Internet. In order to save time, the browser saves a temporary version of the online file on the local hard disk. When you want to recall it, directly display the file on the hard disk instead of the online version. If you want readers to see the latest version every time. , just add this sentence.
2. LINK
Displays the connection relationship between this document and other documents. One of the most useful applications is the positioning of external cascading style sheets. The format is as follows:

The REL parameter describes the relationship between the two documents, and HREF specifies the target document name.
For cascading style sheets, please refer to other articles.
3. BASE
BASE has two main uses:
1.
The original address of this document. In this way, readers can know where they downloaded your document from.
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In a frame page, if you want to display the connection of a certain frame in another frame, for example, to display the connection in the menu frame to the content frame, you can add it to the page in the menu frame. On , there is no need to add the target attribute to the tag of all connections on the menu page, unless the connection is not displayed in the content frame.
4. BODY
The BODY tag has some attributes that are used to define the display effect within the page.
ALINK, LINK, TEXT, VLINK
The color of the text.
ALINK: The text color of the currently activated connection.
TEXT: The color of the text.
VLINK: Visited text color.
Note: The color of the text should be clearly different from the background color to facilitate readers' browsing.
BACKGROUND, BGPROPERTIES, BGCOLOR: The background part of the page.
BACKGROUND: Background pattern, which is tiled within the page. The background pattern should remain a single color to ensure that the text on the page is easy to read.
BGPROPERTIES: Set to FIXED, the background pattern will not scroll. (Only valid for INTERNET EXPLORER)
BGCOLOR: background color.
Note: If your background pattern is dark and the text color is light, then since the order in which the browser calls the page is "background color - text - background pattern", then if the background pattern is not displayed, you The text is difficult to read in white, so choose a background color that matches your background pattern.
LEFTMARGIN, TOPMARGIN: margins. (Only valid for INTERNET EXPLORER)
LEFTMARGIN: Left margin.
TOPMARGIN: Top margin.
MARGINWIDTH, MARGINHEIGHT: margins. (Only valid for NETSCAPE NAVIGATOR)
MARGINWIDTH: left and right margin width
MARGINHEIGHT: top and bottom margin height
Here, for the first time, we encounter the situation where INTERNET EXPLORER and NETSCAPE NAVIGATOR support different tags. Due to the brutal business competition, as the two largest browser software developers, MICROSOFT and NETSCAPE are expanding the functions of HTML and adding some tags that are not available in standard HTML. Due to mutual confidentiality of trade secrets, the two developments have different marks. Fortunately, these two browsers will not report errors for tags they cannot recognize, but simply ignore them. In this way, we can achieve consistent results by adding all the tags they support. For this example, if we want to create a page and use two browsers, the margins are 0, we can write like this:

The same goes for other similar situations. As long as we write them all together, there will generally be no problem.

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