diff --git a/include/xo/alloc2/gc/IAllocator_DX1Collector.hpp b/include/xo/alloc2/gc/IAllocator_DX1Collector.hpp
index f769fd5..138cce8 100644
--- a/include/xo/alloc2/gc/IAllocator_DX1Collector.hpp
+++ b/include/xo/alloc2/gc/IAllocator_DX1Collector.hpp
@@ -36,20 +36,31 @@ namespace xo {
             // todo: available()
 
             static std::string_view name(const DX1Collector &) noexcept;
+            /** reserved memory across all {roles, generations}  **/
             static size_type reserved(const DX1Collector &) noexcept;
             static size_type size(const DX1Collector &) noexcept;
+            /** committed size accross all {roles, generations} **/
             static size_type committed(const DX1Collector &) noexcept;
+            /** available (committed but unused) space across all {roles, generations} **/
             static size_type available(const DX1Collector &) noexcept;
+            /** space used by @p d across all {roles, generations}. **/
             static size_type allocated(const DX1Collector &) noexcept;
+            /** true iff address @p p comes from collector @p d **/
             static bool contains(const DX1Collector & d, const void * p) noexcept;
+            /** report last error, if any, for collector @p d **/
             static AllocatorError last_error(const DX1Collector &) noexcept;
 
+            /** expand gen0 spaces (both from-space and to-space) **/
             static bool expand(DX1Collector & d, size_type z) noexcept;
 
+            /** always alloc in gen0 to-space **//
             static value_type alloc(DX1Collector & d, size_type z);
             static value_type super_alloc(DX1Collector & d, size_type z);
             static value_type sub_alloc(DX1Collector & d, size_type z, bool complete);
+
+            /** reset to empty state; clears all generations **/
             static void clear(DX1Collector & d);
+            /** invoke destructor **/
             static void destruct_data(DX1Collector & d);
         };