Problem description:
This problem usually occurs when developing with UTF-8 encoding.
·In IE, you will find that there is an extra line of blank space in the page, and it is ruled out that it is caused by CSS.
·If you look at the DOM tree in the firebug plug-in for firefox, you will find that there is an extra line of blank space in the HTML, but it has no effect on the page style.
·Put the page code under the hex under UltraEdit and look at it. You will find that where the blank is generated, there will be a "锘? " character, but the original " < " symbol is gone.
If it is a single page, it will appear at the first character position of the page.
If it appears in your include file, it will be at the first character position of the included file.
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illustrate:
This is the problem caused by the UTF-8 signature.
UTF-8 signature, also called BOM (Byte Order Mark), is a standard mark used to identify encoding in the UTF encoding scheme. If multiple files have signatures set, the binary stream will contain multiple UTF-8 signatures, and IE cannot recognize multiple UTF-8 signatures, so use a blank line instead. In some program processing, A character similar to "锘?" will appear.
W3C official description: http://www.w3.org/International/questions/qa-utf8-bom
