See also padding. The margin is a calculated space around any element - a transparent space around any border drawn. Use margin in your stylesheet to remove the need for the deprecated hspace and vspace attributes and to precisely control the relative positioning of page elements. Use margin-top margin-right margin-bottom and margin-left if you want to position the element off center compared to adjacent elements. Setting the margin-left and margin-right to equal values (absolute or relative) will centre the content and
text-align:center; will centre the text.
Meta tags provide a space for information about your page that would be seen by a search engine and the browser but which is not to be displayed. Content-type definitions, search keywords and descriptions, author and copyright content and certain browser functions can all be within a meta tag. All meta tags must be within the <head> section.
<meta http-equiv="expires" content="Sat, 31 Dec 2000 21:29:02 GMT">
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1">
<meta http-equiv="refresh" content="15">
<meta http-equiv="refresh" content="5; URL=http://next">
<meta name="description" content="A real description of your site that truly reflects the content.">
<meta name="keywords" content="designer, source, advice, help">
The mime-type is the data that links the content with an executing program - like an association in Windows. Setting the correct mime type is vital if your pages are to display correctly, especially with multimedia content. The mime type is normally taken from the file extension and the server and browser both have to be configured to determine how the data is handled. Extended types like Shockwave are supported in the browser using plug-ins that act as the intermediary between the HTML and the browser. Most Internet users only come across mime types when they come across a page that requires a plug-in that is not installed on their system but it is important to remember that each mime type has two parts, one that determines how the server handles the requests and one that is installed on each and every system that browses the page. The same user browsing the same page with two browsers often needs two plugins. Some web designers can find that their carefully constructed pages do not function online because the server does not recognize the mime type - in which case all content of that type is simply ignored. Always check that newer technologies are supported by your ISP or webhost, some may have security implications and your request for support may be denied.
A problem with mime types was uncovered with increasing style sheet usage - some ISP's incorrectly set the .css extension to Continuous Slide Show which means that style sheets fail. The server has been configured to use x-application/css not text/css. CSS is now a registered mime type so this problem should have been solved. If your ISP has not solved this error you may have to change ISP. Using the syntax
should prevent your style sheets being mangled. This attribute is required for correct validation of your CSS anyway.