diff --git a/README.markdown b/README.markdown
index 93e15b5..897d0bd 100644
--- a/README.markdown
+++ b/README.markdown
@@ -33,10 +33,8 @@ TODO
 
 For 0.6:
 
-*   `interrupt` routines.
-*   `goto` (tail call).
-*   `vector` type... with declared `inputs` `outputs` `trashes`?
-*   `copy` instruction... that can copy a constant to a user-def mem loc.
+*   declared `inputs` `outputs` `trashes` on the `vector` type.
+*   `goto` (tail call) a routine or a vector.
 *   A more involved demo for the C64 — one that sets up an interrupt.
 
 For 0.7:
@@ -48,8 +46,10 @@ For 0.7:
 
 At some point...
 
+*   `interrupt` routines.
 *   add line number (or at least routine name) to error messages.
 *   6502-mnemonic aliases (`sec`, `clc`)
 *   other handy aliases (`eq` for `z`, etc.)
+*   have `copy` instruction able to copy a constant to a user-def mem loc, etc.
 *   add absolute addressing in shl/shr, absolute-indexed for add, sub, etc.
 *   check and disallow recursion.
diff --git a/doc/SixtyPical.md b/doc/SixtyPical.md
index 7eaddc5..d41eb4a 100644
--- a/doc/SixtyPical.md
+++ b/doc/SixtyPical.md
@@ -83,6 +83,17 @@ A location in memory may be given explicitly on a user-defined memory location.
 
     byte table screen @ 1024
 
+A user-defined vector memory location is decorated with READS and WRITES lists
+like a routine (see below), and it may only hold addresses of routines which
+are compatible.  (Meaning, the routine's inputs (resp. outputs, trashes)
+must be a subset of the vector's inputs (resp. outputs, trashes.))
+
+    vector actor_logic
+      inputs a, score
+      outputs x
+      trashes y
+      @ $c000
+
 Routines
 --------
 
@@ -350,10 +361,10 @@ Grammar
 -------
 
     Program ::= {Defn} {Routine}.
-    Defn    ::= "byte" ["table"] NewIdent ["@" WordConst].
-    Routine ::= "routine" NewIdent
-                ["inputs" LocExprs] ["outputs" LocExprs] ["trashes" LocExprs]
-                (Block | "@" WordConst).
+    Defn    ::= Type NewIdent [Constraints] ["@" WordConst].
+    Type    ::= "byte" ["table"] | "vector"
+    Constrnt::= ["inputs" LocExprs] ["outputs" LocExprs] ["trashes" LocExprs].
+    Routine ::= "routine" NewIdent Constraints (Block | "@" WordConst).
     LocExprs::= LocExpr {"," LocExpr}.
     LocExpr ::= Register | Flag | LitByte | DefnIdent.
     Register::= "a" | "x" | "y".
diff --git a/src/sixtypical/parser.py b/src/sixtypical/parser.py
index 8b41679..ea26f4d 100644
--- a/src/sixtypical/parser.py
+++ b/src/sixtypical/parser.py
@@ -132,17 +132,20 @@ class Parser(object):
         self.scanner.check_type('identifier')
         name = self.scanner.token
         self.scanner.scan()
+
+        (inputs, outputs, trashes) = self.constraints()
+        if type != TYPE_VECTOR and (inputs or outputs or trashes):
+            raise SyntaxError("Cannot apply constraints to non-vector type")
+
         addr = None
         if self.scanner.consume('@'):
             self.scanner.check_type('integer literal')
             addr = int(self.scanner.token)
             self.scanner.scan()            
-        return Defn(name=name, type=type, addr=addr)
+        return Defn(name=name, type=type, addr=addr,
+                    inputs=inputs, outputs=outputs, trashes=trashes)
 
-    def routine(self):
-        self.scanner.expect('routine')
-        name = self.scanner.token
-        self.scanner.scan()
+    def constraints(self):
         inputs = []
         outputs = []
         trashes = []
@@ -152,6 +155,13 @@ class Parser(object):
             outputs = self.locexprs()
         if self.scanner.consume('trashes'):
             trashes = self.locexprs()
+        return (inputs, outputs, trashes)
+
+    def routine(self):
+        self.scanner.expect('routine')
+        name = self.scanner.token
+        self.scanner.scan()
+        (inputs, outputs, trashes) = self.constraints()
         if self.scanner.consume('@'):
             self.scanner.check_type('integer literal')
             block = None
diff --git a/tests/SixtyPical Analysis.md b/tests/SixtyPical Analysis.md
index e0b9db0..f514576 100644
--- a/tests/SixtyPical Analysis.md	
+++ b/tests/SixtyPical Analysis.md	
@@ -989,7 +989,7 @@ Can't `copy` from a memory location that isn't initialized.
     | }
     ? UninitializedAccessError: x
 
-Can't `st` to a memory location that doesn't appear in (outputs ∪ trashes).
+Can't `copy` to a memory location that doesn't appear in (outputs ∪ trashes).
 
     | byte lives
     | routine main
@@ -1036,3 +1036,62 @@ a, z, and n are trashed, and must not be declared as outputs.
     |     copy 0, lives
     | }
     ? UninitializedOutputError: a
+
+Unless of course you subsequently initialize them.
+
+    | byte lives
+    | routine main
+    |   outputs lives, a, z, n
+    | {
+    |     copy 0, lives
+    |     ld a, 0
+    | }
+    = ok
+
+You can copy the address of a routine into a vector, if that vector is declared appropriately.
+
+    | vector vec
+    |   inputs x
+    |   outputs x
+    |   trashes z, n
+    | 
+    | routine foo
+    |   inputs x
+    |   outputs x
+    |   trashes z, n
+    | {
+    |   inc x
+    | }
+    | 
+    | routine main
+    |   inputs foo
+    |   outputs vec
+    |   trashes a, z, n
+    | {
+    |     copy foo, vec
+    | }
+    = ok
+
+But not if the vector is declared inappropriately.
+
+    | vector vec
+    |   inputs y
+    |   outputs y
+    |   trashes z, n
+    | 
+    | routine foo
+    |   inputs x
+    |   outputs x
+    |   trashes z, n
+    | {
+    |   inc x
+    | }
+    | 
+    | routine main
+    |   inputs foo
+    |   outputs vec
+    |   trashes a, z, n
+    | {
+    |     copy foo, vec
+    | }
+    ? IllegalWriteError
diff --git a/tests/SixtyPical Syntax.md b/tests/SixtyPical Syntax.md
index e5d36a5..febf6e2 100644
--- a/tests/SixtyPical Syntax.md	
+++ b/tests/SixtyPical Syntax.md	
@@ -218,6 +218,10 @@ Declaring a byte table memory location.
 Declaring a vector.
 
     | vector cinv
+    |   inputs a
+    |   outputs x
+    |   trashes a, x, z, n
+    |   @ 788
     | 
     | routine foo {
     |     ld a, 0
@@ -228,3 +232,15 @@ Declaring a vector.
     |     }
     | }
     = ok
+
+Only vectors can be decorated with constraints like that.
+
+    | byte cinv
+    |   inputs a
+    |   outputs x
+    |   trashes a, x, z, n
+    |   @ 788
+    | 
+    | routine main {
+    | }
+    ? SyntaxError