No whitespace is stripped

All whitespace text nodes are stripped

Whitespace text nodes other than whitespace within mixed content are stripped. Note that whitespace in text-only content models is considered ignorable under this definition.

Unspecified means that no other value has been specifically requested

Construct the whitespace-stripping policy for a particular XSLT package, as defined by its xsl:strip-space and xsl:preserve-space declarations

Create a custom whitespace stripping policy, by supplying a predicate that indicates for any given element, whether whitespace text nodes among its children should be stripped or preserved. Note that this decision ignores any xml:space attributes that might be present, and the decision applies only to immediate children, not to descendants.