By default the xml parser attempts to allow HTML as "data" within the xml. So tags that are the same name as standard HTML elements are treated as text instead of tags. You can disable this by adding the "nohtml" option to xml.
xml nohtml
trimspace
...
The current list of recognized HTML tags is
"A", "ADDRESS", "APP", "APPLET", "AREA", "B", "BASE", "BASEFONT", "BLOCKQUOTE", "BODY", "BR", "CDATA", "CENTER", "CITE", "CODE", "COMMENT", "DD", "DIR", "DL", "DOCTYPE", "DT", "EM", "FONT", "FORM", "FRAME", "FRAMESET", "H1", "H2", "H3", "H4", "H5", "H6", "HEAD", "HR", "HTML", "I", "IMG", "INPUT", "ISINDEX", "KBD", "LI", "LINK", "LISTING", "MAP", "MENU", "META", "NEXTID", "NOBR", "OL", "OPTION", "P", "PARAM", "PLAINTEXT", "PRE", "SAMP", "SCRIPT", "SELECT", "STRIKE", "STRONG", "TABLE", "TD", "TEXTAREA", "TH", "TITLE", "TR", "TT", "UL", "VAR", "WBR", "XMP"