diff --git a/collects/scribble/scheme.ss b/collects/scribble/scheme.ss
index cfebd12287..1b77a0d26b 100644
--- a/collects/scribble/scheme.ss
+++ b/collects/scribble/scheme.ss
@@ -354,7 +354,7 @@
               (advance c init-line!)
               (when (vector? (syntax-e c))
                 (let ([vec (syntax-e c)])
-                  (out (format "#~a" (vector-length vec)) p-color)
+                  (out "#" #;(format "#~a" (vector-length vec)) p-color)
                   (if (zero? (vector-length vec))
                       (set! src-col (+ src-col (- (syntax-span c) 2)))
                       (set! src-col (+ src-col (- (syntax-column (vector-ref vec 0))
@@ -611,7 +611,7 @@
      [(or (list? v)
           (vector? v))
       (let* ([vec-sz (if (vector? v)
-                         (+ 1 (string-length (format "~a" (vector-length v))))
+                         (+ 1 #;(string-length (format "~a" (vector-length v))))
                          0)])
         (let ([l (let loop ([col (+ col 1 vec-sz)]
                             [v (if (vector? v)
diff --git a/collects/scribblings/guide/vectors.scrbl b/collects/scribblings/guide/vectors.scrbl
index aa770aad6a..26fd3f1bc1 100644
--- a/collects/scribblings/guide/vectors.scrbl
+++ b/collects/scribblings/guide/vectors.scrbl
@@ -10,11 +10,11 @@ values. Unlike a list, a vector supports constant-time access and
 update of its elements.
 
 A vector prints similar to a list---as a parenthesized sequence of its
-elements---but a vector is prefixed with @litchar{#} and the length
-of the vector. The vector length is optional for a vector as an
-expression. Also, a vector as an expression implicitly quotes the
-forms for its content, which means that identifiers and parenthesized
-forms in a vector constant represent symbols and lists.
+elements---but a vector is prefixed with @litchar{#}. For a vector as
+an expression, an optional length can be supplied. Also, a vector as
+an expression implicitly quotes the forms for its content, which means
+that identifiers and parenthesized forms in a vector constant
+represent symbols and lists.
 
 @refdetails/gory["parse-vector"]{the syntax of vectors}
 
diff --git a/collects/scribblings/reference/printer.scrbl b/collects/scribblings/reference/printer.scrbl
index b578d4763f..fbec44a3fd 100644
--- a/collects/scribblings/reference/printer.scrbl
+++ b/collects/scribblings/reference/printer.scrbl
@@ -169,8 +169,9 @@ to three octal digits (only as many as necessary).
 In @scheme[display] mode, the printed form of a vector is @litchar{#}
 followed by the printed form of @scheme[vector->list] applied to the
 vector. In @scheme[write] mode, the printed form is the same, except
-that a decimal integer is printed after the @litchar{#} when the
-@scheme[print-vector-length] parameter is @scheme[#t].
+that when the @scheme[print-vector-length] parameter is @scheme[#t], a
+decimal integer is printed after the @litchar{#}, and a repeated last
+element is printed only once..
 
 @section[#:tag "print-hashtable"]{Printing Hash Tables}
 
diff --git a/collects/scribblings/reference/reader.scrbl b/collects/scribblings/reference/reader.scrbl
index 301e18ed6e..c458591c76 100644
--- a/collects/scribblings/reference/reader.scrbl
+++ b/collects/scribblings/reference/reader.scrbl
@@ -86,14 +86,14 @@ on the next character or characters in the input stream as follows:
   @dispatch[@litchar{[}]{starts a pair or list; see @secref["parse-pair"]}
   @dispatch[@litchar["{"]]{starts a pair or list; see @secref["parse-pair"]}
 
-  @dispatch[@litchar{)}]{matches @litchar{(} or raises @Exn{exn:fail:read}}
-  @dispatch[@litchar{]}]{matches @litchar{[} or raises @Exn{exn:fail:read}}
-  @dispatch[@litchar["}"]]{matches @litchar["{"] or raises @Exn{exn:fail:read}}
+  @dispatch[@litchar{)}]{matches @litchar{(} or raises @Exn[exn:fail:read]}
+  @dispatch[@litchar{]}]{matches @litchar{[} or raises @Exn[exn:fail:read]}
+  @dispatch[@litchar["}"]]{matches @litchar["{"] or raises @Exn[exn:fail:read]}
 
   @dispatch[@litchar{"}]{starts a string; see @secref["parse-string"]}
   @dispatch[@litchar{,}]{starts a quote; see @secref["parse-quote"]}
   @dispatch[@litchar{`}]{starts a quasiquote; see @secref["parse-quote"]}
-  @dispatch[@litchar{,}]{starts an unquote or splicing unquote; see @secref["parse-quote"]}
+  @dispatch[@litchar{,}]{starts an [splicing] unquote; see @secref["parse-quote"]}
 
   @dispatch[@litchar{;}]{starts a line comment; see @secref["parse-comment"]}
 
@@ -117,7 +117,7 @@ on the next character or characters in the input stream as follows:
   @dispatch[@litchar["#! "]]{starts a line comment; see @secref["parse-comment"]}
   @dispatch[@litchar["#!/"]]{starts a line comment; see @secref["parse-comment"]}
   @dispatch[@litchar{#`}]{starts a syntax quasiquote; see @secref["parse-quote"]}
-  @dispatch[@litchar{#,}]{starts an syntax unquote or splicing unquote; see @secref["parse-quote"]}
+  @dispatch[@litchar{#,}]{starts an syntax [splicing] unquote; see @secref["parse-quote"]}
   @dispatch[@litchar["#~"]]{starts compiled code; see @scheme[current-compile]}
 
   @dispatch[@cilitchar{#i}]{starts a number; see @secref["parse-number"]}
@@ -715,7 +715,7 @@ neither defines nor uses graph tags for other top-level forms.
 
 @local-table-of-contents[]
 
-@section[#:tag "parse-reader"]{Reading via an External Reader}
+@section[#:tag "parse-reader"]{Reading via an Extension}
 
 When the reader encounters @as-index{@litchar{#reader}}, then it loads
 an external reader procedure and applies it to the current input
diff --git a/collects/scribblings/reference/write.scrbl b/collects/scribblings/reference/write.scrbl
index bc8656e787..91c9ec0c63 100644
--- a/collects/scribblings/reference/write.scrbl
+++ b/collects/scribblings/reference/write.scrbl
@@ -174,7 +174,7 @@ A parameter that controls printing box values; defaults to
 @defboolparam[print-vector-length on?]{
 
 A parameter that controls printing vectors; defaults to
-@scheme[#t]. See @secref["print-vectors"] for more information.}
+@scheme[#f]. See @secref["print-vectors"] for more information.}
 
 @defboolparam[print-hash-table on?]{
 
diff --git a/doc/release-notes/mzscheme/MzScheme_4.txt b/doc/release-notes/mzscheme/MzScheme_4.txt
index 14aebfa6f6..ebb96b9c47 100644
--- a/doc/release-notes/mzscheme/MzScheme_4.txt
+++ b/doc/release-notes/mzscheme/MzScheme_4.txt
@@ -83,7 +83,11 @@ in several significant ways:
    used carefully; library functions should typically allow "~" to be
    a relative path).
 
- - Hash table printing is enabled by default.
+ - Hash table printing is enabled by default, and vector-length
+   printing is disabled by default. Opaque structure instances no
+   longer print with a leading "struct:" between angle brackets, and
+   built-in procedures print with "procedure:" instead of
+   "primitive:".
 
  - Graph input syntax, such as `#0=(1 . #0#)' is no longer allowed in
    program syntax parsed by `read-syntax', though it is still allowed
diff --git a/src/mzscheme/src/thread.c b/src/mzscheme/src/thread.c
index ac86c8e7f8..8f6c879578 100644
--- a/src/mzscheme/src/thread.c
+++ b/src/mzscheme/src/thread.c
@@ -6263,7 +6263,7 @@ static void make_initial_config(Scheme_Thread *p)
   init_param(cells, paramz, MZCONFIG_PRINT_GRAPH, scheme_false);
   init_param(cells, paramz, MZCONFIG_PRINT_STRUCT, scheme_true);
   init_param(cells, paramz, MZCONFIG_PRINT_BOX, scheme_true);
-  init_param(cells, paramz, MZCONFIG_PRINT_VEC_SHORTHAND, scheme_true);
+  init_param(cells, paramz, MZCONFIG_PRINT_VEC_SHORTHAND, scheme_false);
   init_param(cells, paramz, MZCONFIG_PRINT_HASH_TABLE, scheme_true);
   init_param(cells, paramz, MZCONFIG_PRINT_UNREADABLE, scheme_true);
   init_param(cells, paramz, MZCONFIG_PRINT_PAIR_CURLY, scheme_false);