diff --git a/collects/scribblings/reference/port-buffers.scrbl b/collects/scribblings/reference/port-buffers.scrbl
index 9813500fe9..0d89d95cf9 100644
--- a/collects/scribblings/reference/port-buffers.scrbl
+++ b/collects/scribblings/reference/port-buffers.scrbl
@@ -81,26 +81,27 @@ If @racket[mode] is not provided, the current mode is returned, or
 
 Returns or sets the current read/write position of @racket[port]. 
 
-Calling @racket[file-position] without a position on a
-non-file/non-string input port returns the number of bytes that have
+Calling @racket[file-position] without a position on a port other
+than a @tech{file-stream port} or @tech{string port}
+returns the number of bytes that have
 been read from that port if the position is known (see
 @secref["linecol"]), otherwise the @exnraise[exn:fail:filesystem].
 
-For @tech{file-stream ports} and string ports, the position-setting
+For @tech{file-stream ports} and @tech{string ports}, the position-setting
 variant sets the read/write position to @racket[pos] relative to the
-beginning of the file/string if @racket[pos] is a number, or to the
-current end of the file/string if @racket[pos] is @racket[eof]. In
+beginning of the file or (byte) string if @racket[pos] is a number, or to the
+current end of the file or (byte) string if @racket[pos] is @racket[eof]. In
 position-setting mode, @racket[file-position] raises the
 @racket[exn:fail:contract] exception for port kinds other than
-file-stream and string ports. Furthermore, not all @tech{file-stream
+@tech{file-stream ports} and @tech{string ports}. Furthermore, not all @tech{file-stream
 ports} support setting the position; if @racket[file-position] is
 called with a position argument on such a @tech{file-stream port}, the
 @exnraise[exn:fail:filesystem].
 
 When @racket[file-position] sets the position @racket[pos] beyond the
-current size of an output file or string, the file/string is enlarged
+current size of an output file or (byte) string, the file/string is enlarged
 to size @racket[pos] and the new region is filled with @racket[0]
-bytes.  If @racket[pos] is beyond the end of an input file or string,
+bytes.  If @racket[pos] is beyond the end of an input file or (byte) string,
 then reading thereafter returns @racket[eof] without changing the
 port's position.
 
diff --git a/collects/scribblings/reference/string-ports.scrbl b/collects/scribblings/reference/string-ports.scrbl
index 13e6c01e1b..9418d4a319 100644
--- a/collects/scribblings/reference/string-ports.scrbl
+++ b/collects/scribblings/reference/string-ports.scrbl
@@ -3,26 +3,33 @@
 
 @title[#:tag "stringport"]{String Ports}
 
-String input and output ports do not need to be explicitly closed. The
-@racket[file-position] procedure works for string ports in
-position-setting mode.
+A @deftech{string port} reads or writes from a @tech{byte string}. An
+input @tech{string port} can be created from either a @tech{byte string} or a
+@tech{string}; in the latter case, the @tech{string} is effectively converted to
+a @tech{byte string} using @racket[string->bytes/utf-8]. An output @tech{string port}
+collects output into a @tech{byte string}, but @racket[get-output-string]
+conveniently converts the accumulated bytes to a @tech{string}.
+
+Input and output @tech{string ports} do not need to be explicitly
+closed. The @racket[file-position] procedure works for @tech{string
+ports} in position-setting mode.
 
 @defproc[(open-input-bytes [bstr bytes?] [name any/c 'string]) input-port?]{
 
-Creates an input port that reads characters from @racket[bstr] (see
+Creates an input @tech{string port} that reads characters from @racket[bstr] (see
 @secref["bytestrings"]). Modifying @racket[bstr] afterward does not
 affect the byte stream produced by the port. The optional
 @racket[name] argument is used as the name for the returned port.}
 
 @defproc[(open-input-string [str string?] [name any/c 'string]) input-port?]{
 
-Creates an input port that reads bytes from the UTF-8 encoding (see
+Creates an input @tech{string port} that reads bytes from the UTF-8 encoding (see
 @secref["encodings"]) of @racket[str]. The optional @racket[name]
 argument is used as the name for the returned port.}
 
 @defproc[(open-output-bytes [name any/c 'string]) output-port?]{
 
-Creates an output port that accumulates the output into a byte
+Creates an output @tech{string port} that accumulates the output into a byte
 string. The optional @racket[name] argument is used as the name for
 the returned port.}
 
@@ -35,10 +42,10 @@ same as @racket[open-output-bytes].}
                            [end-pos exact-nonnegative-integer? #f])
          bytes?]{
 
-Returns the bytes accumulated in @racket[out] so far in a
-freshly allocated byte string (including any bytes written after the
-port's current position, if any). The @racket[out] port must be a
-string output port produced by @racket[open-output-bytes] (or
+Returns the bytes accumulated in the @tech{string port} @racket[out] so far in a
+freshly allocated @tech{byte string} (including any bytes written after the
+port's current position, if any). The @racket[out] port must be an
+output @tech{string port} produced by @racket[open-output-bytes] (or
 @racket[open-output-string]) or a structure whose
 @racket[prop:output-port] property refers to such an output port
 (transitively).