diff --git a/scan/is/is.go b/scan/is/is.go
index aa9a7d0..0e855d2 100644
--- a/scan/is/is.go
+++ b/scan/is/is.go
@@ -11,10 +11,12 @@ easily generate the other.
 
 Nodes and Expressions
 
-Nodes (z.N) indicate something to be captured as a part of the resulting
+Nodes (z.Nd) indicate something to be captured as a part of the resulting
 abstract syntax tree. They are functionally equivalent to parenthesis in
 regular expressions but with the obvious advantage of capturing a rooted
-node tree instead of an array. Expressions (z.X) indicate a sequence to be scanned but not captured unless the expression itself is within a node (z.N).
+node tree instead of an array. Expressions (z.X) indicate a sequence to
+be scanned but not captured unless the expression itself is within
+a node (z.Nd).
 
 Tokens
 
@@ -59,16 +61,16 @@ package z
 
 // ------------------------------- core -------------------------------
 
-// N ("node") is a named sequence of expressions that will be captured
+// Nd ("node") is a named sequence of expressions that will be captured
 // into a node. The first string must always be the name which can be
 // any valid Go string. If any expression fails to match the scan fails.
 // Otherwise, a new tree.Node is added under the current node and the
 // scan proceeds. Nodes must either contain other nodes or no nodes at
 // all. If the first item in the sequence after the name is not also
-// a node (z.N) then the node is marked as "edge" (or "leaf") and any
+// a node (z.Nd) then the node is marked as "edge" (or "leaf") and any
 // nodes detected further in the sequence will cause the scan to fail
 // with a syntax error.
-type N []any
+type Nd []any
 
 // X ("expression") is a sequence of expressions.  If any are not the
 // scan fails. (Equal to (?foo) in regular expressions.)
@@ -76,20 +78,20 @@ type X []any
 
 // ------------------------------- sets -------------------------------
 
-// It (the slice) is a set of positive lookahead expressions. If any are
+// It ("is it") is a set of positive lookahead expressions. If any are
 // seen at the current cursor position the scan will proceed without
 // consuming them (unlike is.O and is.In). If none are found the scan
 // fails. This is useful when everything from one expression is wanted
 // except for a few positive exceptions. (Equal to ampersand (&) in
-// PEGN.) Also see the tk.IS token.
+// PEGN.)
 type It []any
 
-// Not (the slice) is a set of negative lookahead expressions. If any
-// are seen at the current cursor position the scan will fail and the
-// scan is never advanced. This is useful when everything from one
-// expression is wanted except for a few negative exceptions. (Equal to
-// exclamation point (!) in PEGN.) Also see the tk.NOT token.
-type Not []any
+// N ("not") is a set of negative lookahead expressions. If any are seen
+// at the current cursor position the scan will fail and the scan is
+// never advanced. This is useful when everything from one expression is
+// wanted except for a few negative exceptions. (Equal to exclamation
+// point (!) in PEGN.)
+type N []any
 
 // In is a set of advancing expressions. If any expression in the slice
 // is found the scan advances to the end of that expression and
diff --git a/scan/scan.go b/scan/scan.go
index 6132c84..630467a 100644
--- a/scan/scan.go
+++ b/scan/scan.go
@@ -367,7 +367,7 @@ func (s *R) Expect(expr any) (*Cur, error) {
 		s.Jump(b)
 		return b, nil
 
-	case z.Not: // ----------------------------------------------------
+	case z.N: // ----------------------------------------------------
 		m := s.Mark()
 		for _, i := range v {
 			if c, _ := s.Expect(i); c != nil {
@@ -517,7 +517,7 @@ func (s *R) ErrorExpected(this any, args ...any) error {
 		} else {
 			msg = fmt.Sprintf(`expected %q`, v[0])
 		}
-	case z.Not:
+	case z.N:
 		msg = fmt.Sprintf(`unexpected %q`, args[0])
 	case z.In:
 		str := `expected one of %q`
diff --git a/scan/scan_test.go b/scan/scan_test.go
index 8f9b612..da9f51e 100644
--- a/scan/scan_test.go
+++ b/scan/scan_test.go
@@ -266,7 +266,7 @@ func ExampleExpect_it_Fail_X() {
 
 func ExampleExpect_not_Success() {
 	s, _ := scan.New("some thing")
-	c, _ := s.Expect(z.Not{"foo"})
+	c, _ := s.Expect(z.N{"foo"})
 	c.Print() // not advanced, but also not <nil>
 	s.Print() // not advanced at all
 	// Output:
@@ -276,7 +276,7 @@ func ExampleExpect_not_Success() {
 
 func ExampleExpect_not_Fail() {
 	s, _ := scan.New("some thing")
-	_, err := s.Expect(z.Not{"some"})
+	_, err := s.Expect(z.N{"some"})
 	fmt.Println(err)
 	s.Print() // not advanced at all
 	// Output:
@@ -286,7 +286,7 @@ func ExampleExpect_not_Fail() {
 
 func ExampleExpect_not_X_Fail() {
 	s, _ := scan.New("some thing wonderful")
-	_, err := s.Expect(z.X{z.Not{'s'}, 'o'})
+	_, err := s.Expect(z.X{z.N{'s'}, 'o'})
 	fmt.Println(err) // sees the s so fails
 	s.Print()        // not advanced
 	// Output:
@@ -296,7 +296,7 @@ func ExampleExpect_not_X_Fail() {
 
 func ExampleExpect_not_X_Success() {
 	s, _ := scan.New("some thing wonderful")
-	c, _ := s.Expect(z.X{z.Not{`n`}, z.In{`som`}})
+	c, _ := s.Expect(z.X{z.N{`n`}, z.In{`som`}})
 	c.Print() // pointing to last in match 'm'
 	s.Print() // advanced to next after match 'e'
 	// Output:
@@ -331,12 +331,12 @@ func ExampleExpect_in() {
 func ExampleExpect_avoid_Not_with_In() {
 	s, _ := scan.New("some thing")
 	s.Snap()
-	c, _ := s.Expect(z.In{z.Not{'s'}, z.R{'a', 'z'}})
+	c, _ := s.Expect(z.In{z.N{'s'}, z.R{'a', 'z'}})
 	c.Print() // unexpected success
 	s.Print() // advanced to 'o'
 	s.Back()
 	// use z.X instead
-	_, err := s.Expect(z.X{z.Not{'s'}, z.R{'a', 'z'}})
+	_, err := s.Expect(z.X{z.N{'s'}, z.R{'a', 'z'}})
 	fmt.Println(err)
 	s.Print() // not advanced
 	// Output:
@@ -368,7 +368,7 @@ func ExampleExpect_seq_Fail() {
 
 func ExampleExpect_seq_Not_Success() {
 	s, _ := scan.New("some thing")
-	c, _ := s.Expect(z.X{"some", ` `, z.Not{`T`}, "thin"})
+	c, _ := s.Expect(z.X{"some", ` `, z.N{`T`}, "thin"})
 	c.Print() // same as "some thin"
 	s.Print() // advanced to next after ('g')
 	// Output:
@@ -378,7 +378,7 @@ func ExampleExpect_seq_Not_Success() {
 
 func ExampleExpect_seq_Not_Fail() {
 	s, _ := scan.New("some Thing")
-	_, err := s.Expect(z.X{"some", ' ', z.Not{`T`}, "ignored"})
+	_, err := s.Expect(z.X{"some", ' ', z.N{`T`}, "ignored"})
 	fmt.Println(err)
 	s.Print() // not advanced at all
 	// Output: