This procedure is defined in the server but not documented via ad_proc or proc_doc and may be intended as a private interface.
The procedure is defined as:
proc dom::Serialize:XMLDecl {attr attrList} {
array set data $attrList
if {![info exists data($attr)]} {
return {}
} elseif {[string length $data($attr)]} {
return " $attr='$data($attr)'"
} else {
return {}
}
}