compiling the following simple idl:
================================
module A {
    interface Holder;
};

interface B {
    typedef A::Holder ap;
    attribute ap bp;
};
================================
with "-sloppy_forward -W 4" option you get:


   [ /tmp/p.idl ]
   [ checking module name A ]
   [ ScopedName.setId A ]
   [ ScopedName.setId A.Holder ]
   [ ScopedName.escapeName A._Holder ]
   [ ScopedName.setId ap ]
   [ NameTable.define2: putting A kind module hash: 65 ]
   [ NameTable.checkScopingRules:  A kind: module ]
   [ NameTable.checkScopingRules2:  A kind: module ]
   [ NameTable.define2: putting A.Holder kind interface hash: 1656144921 ]
   [ NameTable.checkScopingRules:  A.Holder kind: interface ]
   [ NameTable.checkScopingRules2:  A.Holder kind: interface ]
   [ Typedef'ing A.Holder for  , hash: 503498 ]
   [ NameTable.define2: putting B kind interface hash: 66 ]
   [ NameTable.checkScopingRules:  B kind: interface ]
   [ NameTable.checkScopingRules2:  B kind: interface ]
   [ Typedef'ing B for  , hash: 6589979 ]
   [ Interface Body parse B ]
   [ Interface Body internal_parse B ]
   [ Resolve B:A._Holder ]
Error in p.idl, line:6(22): Undefined name: B.A._Holder
	    typedef A::Holder
Can't recover from previous error(s), giving up.

The same thing happens to all other keywords such as Helper, POA, POATie, 
Package.