* The MIME standard can be used to tell the browsers about the automatic identification and handling of files.
* We can mention the MIME type in a HTML page by using META tag. for example,
<meta http-equiv='Content-Type' content='application/xhtml+xml; charset=UTF-8' />
* Yellow Screen of Death (YSOD) occurs when a XHTML document is having any markup errors like missing tags, improper closing tags etc..
* As long as we are using XHTML1.0 we no need to worry about the MIME type, but if we are using XHTML1.1, must and should we have to mention the MIME Type(Typically application/xhtml+xml).
* Namespacing is the concept of making our code to follow certain naming conventions thereby making our programs more portable, easy to maintain, avoiding the conflicts if we include our code in other documents of similar type.