[malvinas2]

In Python it is common to use 4 spaces per indentation level. The Python interpreter will however recognize spaces or tabs. The only gottcha is you must never mix spaces and tabs, pick one or the other. 
Does the Kodi skinning engine behave in the same way or can I mix spaces and tabs within the xml-files?

[ronie]

you can use tabs, spaces, a mixture of both or no indenting at all, it doesn't matter for .xml files.