In many questions, we see the source code with wrong indentation. On of the reasons for it, if the copy/pasted code contains tabs, the assumed tab size in the edit box is different from the assumed tab size in the final view. For instance, the following lines appear vertically aligned in the edit box, but in the final code view, they are not.
line one line two
It looks like the edit box view is correct and the rendered view is broken.
While typing manually it is not possible to enter the tab at all (the focus simply leaves the edit window), a code if often copy-pasted from some IDE. After that it quite often must be manually re-aligned, unnecessarily consuming the editor time.