No explanation of "action" and "new" in channel type defns

2.3.4 Channel Types

<channelType  name="ncname"
     usage="once"|"unlimited"?
     action="request-respond"|"request"|"respond"? >
   <passing  channel="qname"
         action="request-respond"|"request"|"respond"?
         new="xsd:boolean"? />*
   <role  type="qname"  behavior="ncname"? />
   <reference>
      <token type="qname"/>
   </reference>
   <identity>
      <token  type="qname"/>+
   </identity>?
</channelType>


There is no explanation of "action" after "usage".
There is no explanation of "new" after "action".