diff --git a/doc/Checking.markdown b/doc/Checking.markdown
index 194b812..7f8e121 100644
--- a/doc/Checking.markdown
+++ b/doc/Checking.markdown
@@ -123,6 +123,35 @@ Test for many combinations of `reserve` and `assign`.
     | }
     = True
 
+`reserve` may be block-level.
+
+    | routine main {
+    |    reserve byte lives
+    |    lda lives
+    | }
+    = True
+
+Block-level declarations are only visible in the block in which they are
+declared.
+
+    | routine main {
+    |    reserve byte lives
+    |    lda #3
+    |    sta lives
+    | }
+    | routine died {
+    |    dec lives
+    | }
+    ? undeclared location 'lives'
+
+A block-level `reserve` may not supply an initial value.
+
+    | routine main {
+    |    reserve byte lives : 3
+    |    lda lives
+    | }
+    ? block-level 'lives' cannot supply initial value
+
 A program may declare an `external`.
 
     | external blastoff 49152
diff --git a/src/SixtyPical/Transformer.hs b/src/SixtyPical/Transformer.hs
index ca13820..b050d33 100644
--- a/src/SixtyPical/Transformer.hs
+++ b/src/SixtyPical/Transformer.hs
@@ -169,7 +169,8 @@ foldDeclsRenaming ((Reserve name typ Nothing):decls) id block =
         block'' = substDeclName name newName block'
     in
         foldDeclsRenaming decls id' block''
-
+foldDeclsRenaming ((Reserve name typ _):decls) id block =
+    error ("block-level '" ++ name ++ "' cannot supply initial value")
 
 -- this is kind of horrible.  that we do it this way, i mean
 substDeclName n1 n2 (Block decls instrs) =
@@ -198,16 +199,22 @@ mapInstrName n1 n2 (SUB sl1 sl2) =
    SUB (mapStorageLocationName n1 n2 sl1) (mapStorageLocationName n1 n2 sl2)
 mapInstrName n1 n2 (OR sl1 sl2) =
    OR (mapStorageLocationName n1 n2 sl1) (mapStorageLocationName n1 n2 sl2)
+mapInstrName n1 n2 (XOR sl1 sl2) =
+   XOR (mapStorageLocationName n1 n2 sl1) (mapStorageLocationName n1 n2 sl2)
+mapInstrName n1 n2 (SHL sl1 sl2) =
+   SHL (mapStorageLocationName n1 n2 sl1) (mapStorageLocationName n1 n2 sl2)
+mapInstrName n1 n2 (SHR sl1 sl2) =
+   SHR (mapStorageLocationName n1 n2 sl1) (mapStorageLocationName n1 n2 sl2)
+mapInstrName n1 n2 (BIT sl1) =
+   BIT (mapStorageLocationName n1 n2 sl1)
+mapInstrName n1 n2 (JMPVECTOR sl1) =
+   JMPVECTOR (mapStorageLocationName n1 n2 sl1)
+mapInstrName n1 n2 (DELTA sl1 v) =
+   DELTA (mapStorageLocationName n1 n2 sl1) v
 
 {-
-                 | XOR StorageLocation StorageLocation
-                 | SHL StorageLocation StorageLocation
-                 | SHR StorageLocation StorageLocation
-                 | BIT StorageLocation
-                 | JMPVECTOR StorageLocation
                  | IF InternalID Branch Block Block
                  | REPEAT InternalID Branch Block
-                 | DELTA StorageLocation DataValue
                  | WITH WithInstruction Block
                  | COPYROUTINE RoutineName StorageLocation
 -}