diff --git a/icu4c/source/common/cmemory.h b/icu4c/source/common/cmemory.h
index e84517e..2d37b91 100644
--- a/icu4c/source/common/cmemory.h
+++ b/icu4c/source/common/cmemory.h
@@ -297,6 +297,9 @@
      * Automatically allocates the heap array if the argument is larger than the stack capacity.
      * Intended for use when an approximate capacity is known at compile time but the true
      * capacity is not known until runtime.
+     *
+     * WARNING: does not report errors upon memory allocation failure, after
+     * which capacity will be stackCapacity, not the requested newCapacity.
      */
     MaybeStackArray(int32_t newCapacity) : MaybeStackArray() {
         if (capacity < newCapacity) { resize(newCapacity); }
@@ -396,11 +399,11 @@
         needToRelease=FALSE;
     }
     /* No comparison operators with other MaybeStackArray's. */
-    bool operator==(const MaybeStackArray & /*other*/) {return FALSE;}
-    bool operator!=(const MaybeStackArray & /*other*/) {return TRUE;}
+    bool operator==(const MaybeStackArray & /*other*/) = delete;
+    bool operator!=(const MaybeStackArray & /*other*/) = delete;
     /* No ownership transfer: No copy constructor, no assignment operator. */
-    MaybeStackArray(const MaybeStackArray & /*other*/) {}
-    void operator=(const MaybeStackArray & /*other*/) {}
+    MaybeStackArray(const MaybeStackArray & /*other*/) = delete;
+    void operator=(const MaybeStackArray & /*other*/) = delete;
 };
 
 template<typename T, int32_t stackCapacity>