diff --git a/include/xo/reader2/DGlobalEnv.hpp b/include/xo/reader2/DGlobalEnv.hpp
index 04605c4c..6bb88f49 100644
--- a/include/xo/reader2/DGlobalEnv.hpp
+++ b/include/xo/reader2/DGlobalEnv.hpp
@@ -27,7 +27,7 @@ namespace xo {
         class DGlobalEnv {
         public:
             using TypeDescr = xo::reflect::TypeDescr;
-            using ACollector = xo::mm::ACollector;
+            //using ACollector = xo::mm::ACollector;
             using AGCObject = xo::mm::AGCObject;
             using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
             using AAllocator = xo::mm::AAllocator;
@@ -72,7 +72,7 @@ namespace xo {
             /** @defgroup scm-globalenv-gcobject-facet **/
             ///@{
 
-            DGlobalEnv * shallow_move(obj<ACollector> gc) noexcept;
+            DGlobalEnv * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
             void visit_gco_children(obj<AGCObjectVisitor> gc) noexcept;
 
             ///@}
diff --git a/include/xo/reader2/env/IGCObject_DGlobalEnv.hpp b/include/xo/reader2/env/IGCObject_DGlobalEnv.hpp
index 2b961b43..f96deebc 100644
--- a/include/xo/reader2/env/IGCObject_DGlobalEnv.hpp
+++ b/include/xo/reader2/env/IGCObject_DGlobalEnv.hpp
@@ -53,8 +53,9 @@ namespace xo {
             // const methods
 
             // non-const methods
-            /** move instance using collector **/
-            static Opaque shallow_move(DGlobalEnv & self, obj<ACollector> gc) noexcept;
+            /** move instance using object visitor.
+Arguably abusing the word 'visitor' here **/
+            static Opaque gco_shallow_move(DGlobalEnv & self, obj<AGCObjectVisitor> gc) noexcept;
             /** Invoke fn.visit_child(iface,data) for each child GCObject pointer.
 Context: provides address of data pointer so it can be updated in place
 when @p fn invokes garbage collector reentry point **/
diff --git a/include/xo/reader2/parser/DSchematikaParser.hpp b/include/xo/reader2/parser/DSchematikaParser.hpp
index c3de4930..24e4b46a 100644
--- a/include/xo/reader2/parser/DSchematikaParser.hpp
+++ b/include/xo/reader2/parser/DSchematikaParser.hpp
@@ -164,7 +164,7 @@ namespace xo {
             using token_type = Token;
             using ArenaHashMapConfig = xo::map::ArenaHashMapConfig;
             using ArenaConfig = xo::mm::ArenaConfig;
-            using ACollector = xo::mm::ACollector;
+            //using ACollector = xo::mm::ACollector;
             using AGCObject = xo::mm::AGCObject;
             using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
             using AAllocator = xo::mm::AAllocator;
@@ -295,7 +295,7 @@ namespace xo {
             ///@{
 
             /** not implemented (SchematikaParser not designed to be copyable) **/
-            DSchematikaParser * shallow_move(obj<ACollector> gc) noexcept;
+            DSchematikaParser * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
             /** forward gc-aware children **/
             void visit_gco_children(obj<AGCObjectVisitor> gc) noexcept;
 
diff --git a/include/xo/reader2/parser/IGCObject_DSchematikaParser.hpp b/include/xo/reader2/parser/IGCObject_DSchematikaParser.hpp
index ce93ba8a..64394e65 100644
--- a/include/xo/reader2/parser/IGCObject_DSchematikaParser.hpp
+++ b/include/xo/reader2/parser/IGCObject_DSchematikaParser.hpp
@@ -53,8 +53,9 @@ namespace xo {
             // const methods
 
             // non-const methods
-            /** move instance using collector **/
-            static Opaque shallow_move(DSchematikaParser & self, obj<ACollector> gc) noexcept;
+            /** move instance using object visitor.
+Arguably abusing the word 'visitor' here **/
+            static Opaque gco_shallow_move(DSchematikaParser & self, obj<AGCObjectVisitor> gc) noexcept;
             /** Invoke fn.visit_child(iface,data) for each child GCObject pointer.
 Context: provides address of data pointer so it can be updated in place
 when @p fn invokes garbage collector reentry point **/
diff --git a/src/reader2/DGlobalEnv.cpp b/src/reader2/DGlobalEnv.cpp
index 64eabd4f..8491c60b 100644
--- a/src/reader2/DGlobalEnv.cpp
+++ b/src/reader2/DGlobalEnv.cpp
@@ -108,7 +108,7 @@ namespace xo {
         // ----- AGCObject facet -----
 
         DGlobalEnv *
-        DGlobalEnv::shallow_move(obj<ACollector> gc) noexcept
+        DGlobalEnv::gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept
         {
             return gc.std_move_for<DGlobalEnv>(this);
         }
diff --git a/src/reader2/DSchematikaParser.cpp b/src/reader2/DSchematikaParser.cpp
index 1d5ecea7..fc71d12f 100644
--- a/src/reader2/DSchematikaParser.cpp
+++ b/src/reader2/DSchematikaParser.cpp
@@ -185,7 +185,7 @@ namespace xo {
         }
 
         DSchematikaParser *
-        DSchematikaParser::shallow_move(obj<ACollector> gc) noexcept
+        DSchematikaParser::gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept
         {
             (void)gc;
 
diff --git a/src/reader2/facet/IGCObject_DGlobalEnv.cpp b/src/reader2/facet/IGCObject_DGlobalEnv.cpp
index e826c422..9a2802ae 100644
--- a/src/reader2/facet/IGCObject_DGlobalEnv.cpp
+++ b/src/reader2/facet/IGCObject_DGlobalEnv.cpp
@@ -16,9 +16,9 @@
 namespace xo {
     namespace scm {
         auto
-        IGCObject_DGlobalEnv::shallow_move(DGlobalEnv & self, obj<ACollector> gc) noexcept -> Opaque
+        IGCObject_DGlobalEnv::gco_shallow_move(DGlobalEnv & self, obj<AGCObjectVisitor> gc) noexcept -> Opaque
         {
-            return self.shallow_move(gc);
+            return self.gco_shallow_move(gc);
         }
         auto
         IGCObject_DGlobalEnv::visit_gco_children(DGlobalEnv & self, obj<AGCObjectVisitor> fn) noexcept -> void
diff --git a/src/reader2/facet/IGCObject_DSchematikaParser.cpp b/src/reader2/facet/IGCObject_DSchematikaParser.cpp
index cd9ec847..f1778d5a 100644
--- a/src/reader2/facet/IGCObject_DSchematikaParser.cpp
+++ b/src/reader2/facet/IGCObject_DSchematikaParser.cpp
@@ -16,9 +16,9 @@
 namespace xo {
     namespace scm {
         auto
-        IGCObject_DSchematikaParser::shallow_move(DSchematikaParser & self, obj<ACollector> gc) noexcept -> Opaque
+        IGCObject_DSchematikaParser::gco_shallow_move(DSchematikaParser & self, obj<AGCObjectVisitor> gc) noexcept -> Opaque
         {
-            return self.shallow_move(gc);
+            return self.gco_shallow_move(gc);
         }
         auto
         IGCObject_DSchematikaParser::visit_gco_children(DSchematikaParser & self, obj<AGCObjectVisitor> fn) noexcept -> void