Please make sure you have read the Tag Syntax document and understand how tag attribute syntax works.

{snippet:id=javadoc|javadoc=true|url=org.apache.struts2.components.Head}

{snippet:id=tagattributes|javadoc=false|url=struts2-tags/head.html}

{snippet:id=example1|lang=xml|javadoc=true|url=org.apache.struts2.components.Head}