https://bugs.php.net/bug.php?id=33305&edit=1
PHP :: Bug #33305 :: appendChild adds additionnal namespace on wrong node
phpbugaddsnamespacewrong
https://www.php.net/manual/zh/domnode.appendchild.php
PHP: DOMNode::appendChild - Manual
Adds new child at the end of the children
phpmanual
https://magicmac.github.io/blog/2010-12-01-ie9-dos-deadcall-createdocumentfragment-appendchild/
IE9 Crash (Deadcall): appendChild on a Dead createDocumentFragment
on acrashdead
https://developer.mozilla.org/en-US/docs/Web/API/Node/appendChild
Node: appendChild() method - Web APIs | MDN
The appendChild() method of the Node interface adds a node to the end of the list of children of a specified parent node.
web apisnodemethodmdn
https://learn.microsoft.com/en-us/dotnet/api/system.xml.xmlnode.appendchild?view=netframework-4.8.1&redirectedfrom=MSDN
XmlNode.AppendChild(XmlNode) Method (System.Xml) | Microsoft Learn
Adds the specified node to the end of the list of child nodes, of this node.
methodsystemxmlmicrosoftlearn