2.2.1 [XML] Section 2.1, White Space Handling
The value "default" signals that applications' default white-space processing modes are acceptable for this element; the value "preserve" indicates the intent that applications preserve all the white space. This declared intent is considered to apply to all elements within the content of the element where it is specified, unless overridden with another instance of the xml:space attribute. This specification does not give meaning to any value of xml:space other than "default" and "preserve". It is an error for other values to be specified; the XML processor MAY report the error or MAY recover by ignoring the attribute specification or by reporting the (erroneous) value to the application. Applications may ignore or reject erroneous values.
IE9 Mode, IE10 Mode, IE11 Mode, and EdgeHTML Mode (All Versions)
An error is reported if the xml:space attribute is
used with a value other than