diff --git a/lib/libc/sys/accept.2 b/lib/libc/sys/accept.2
index 736d0681dfb2..badb2b113b49 100644
--- a/lib/libc/sys/accept.2
+++ b/lib/libc/sys/accept.2
@@ -132,30 +132,6 @@ by issuing a
 call providing only the control information,
 or by calling
 .Xr setsockopt 2 .
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn accept
-is implemented as the
-.Va accept
-syscall.
-.Pp
-In the threaded library, the
-.Va accept
-syscall is assembled to
-.Fn _thread_sys_accept
-and
-.Fn accept
-is implemented as a function which locks
-.Fa s
-for read and write, then calls
-.Fn _thread_sys_accept .
-If the call to
-.Fn _thread_sys_accept
-would block, a context switch is performed.
-Before returning,
-.Fn accept
-unlocks
-.Fa s .
 .Sh RETURN VALUES
 The call returns \-1 on error.  If it succeeds, it returns a non-negative
 integer that is a descriptor for the accepted socket.
diff --git a/lib/libc/sys/bind.2 b/lib/libc/sys/bind.2
index 4e99aa883a0d..cda98221c9c0 100644
--- a/lib/libc/sys/bind.2
+++ b/lib/libc/sys/bind.2
@@ -68,27 +68,6 @@ Consult the manual entries in section 4 for detailed information.
 For maximum portability, you should always zero-out the socket structure
 before populating it, before passing it to
 .Fn bind .
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn bind
-is implemented as the
-.Va bind
-syscall.
-.Pp
-In the threaded library, the
-.Va bind
-syscall is assembled to
-.Fn _thread_sys_bind
-and
-.Fn bind
-is implemented as a function which locks
-.Fa s
-for read and write, then calls
-.Fn _thread_sys_bind .
-Before returning,
-.Fn bind
-unlocks
-.Fa s .
 .Sh RETURN VALUES
 .Rv -std bind
 .Sh ERRORS
diff --git a/lib/libc/sys/close.2 b/lib/libc/sys/close.2
index 9192ae15be12..6a0719147fa6 100644
--- a/lib/libc/sys/close.2
+++ b/lib/libc/sys/close.2
@@ -101,27 +101,6 @@ execve; the call
 .Dq Li fcntl(d, F_SETFD, 0)
 restores the default,
 which is to not close the descriptor.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn close
-is implemented as the
-.Va close
-syscall.
-.Pp
-In the threaded library, the
-.Va close
-syscall is assembled to
-.Fn _thread_sys_close
-and
-.Fn close
-is implemented as a function which locks
-.Fa d
-for read and write, then calls
-.Fn _thread_sys_close .
-Before returning,
-.Fn close
-unlocks
-.Fa d .
 .Sh RETURN VALUES
 .Rv -std close
 .Sh ERRORS
diff --git a/lib/libc/sys/connect.2 b/lib/libc/sys/connect.2
index 975b6c67b667..c80f03dd583f 100644
--- a/lib/libc/sys/connect.2
+++ b/lib/libc/sys/connect.2
@@ -71,30 +71,6 @@ only once; datagram sockets may use
 multiple times to change their association.
 Datagram sockets may dissolve the association
 by connecting to an invalid address, such as a null address.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn connect
-is implemented as the
-.Va connect
-syscall.
-.Pp
-In the threaded library, the
-.Va connect
-syscall is assembled to
-.Fn _thread_sys_connect
-and
-.Fn connect
-is implemented as a function which locks
-.Va s
-for read and write, then calls
-.Fn _thread_sys_connect .
-If the call to
-.Fn _thread_sys_connect
-would block, a context switch is performed.
-Before returning,
-.Fn connect
-unlocks
-.Va s .
 .Sh RETURN VALUES
 .Rv -std connect
 .Sh ERRORS
diff --git a/lib/libc/sys/dup.2 b/lib/libc/sys/dup.2
index d9a7a3f53413..2d57eab0d18b 100644
--- a/lib/libc/sys/dup.2
+++ b/lib/libc/sys/dup.2
@@ -115,52 +115,6 @@ and
 is a valid descriptor, then
 .Fn dup2
 is successful, and does nothing.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn dup
-is implemented as the
-.Va dup
-syscall.
-.Pp
-In the threaded library, the
-.Va dup
-syscall is assembled to
-.Fn _thread_sys_dup
-and
-.Fn dup
-is implemented as a function which locks
-.Fa oldd
-for read and write, then calls
-.Fn _thread_sys_dup .
-Before returning,
-.Fn dup
-unlocks
-.Fa oldd .
-.Pp
-In the non-threaded library
-.Fn dup2
-is implemented as the
-.Va dup2
-syscall.
-.Pp
-In the threaded library, the
-.Va dup2
-syscall is assembled to
-.Fn _thread_sys_dup2
-and
-.Fn dup2
-is implemented as a function which locks both
-.Fa oldd
-and
-.Fa newd
-for read and write, then calls
-.Fn _thread_sys_dup2 .
-Before returning,
-.Fn dup2
-unlocks
-.Fa oldd .
-and
-.Fa newd .
 .Sh RETURN VALUES
 The value -1 is returned if an error occurs in either call.
 The external variable
diff --git a/lib/libc/sys/execve.2 b/lib/libc/sys/execve.2
index 89c0ecb3085f..56aefcf2dbe4 100644
--- a/lib/libc/sys/execve.2
+++ b/lib/libc/sys/execve.2
@@ -189,22 +189,6 @@ and
 .Fa argv
 points to the array of character pointers
 to the arguments themselves.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn execve
-is implemented as the
-.Va execve
-syscall.
-.Pp
-In the threaded library, the
-.Va execve
-syscall is assembled to
-.Fn _thread_sys_execve
-and
-.Fn execve
-is implemented as a function which performs user-thread
-library re-initialization and then calls
-.Fn _thread_sys_execve .
 .Sh RETURN VALUES
 As the
 .Fn execve
diff --git a/lib/libc/sys/fcntl.2 b/lib/libc/sys/fcntl.2
index f416903ed05a..2f70e72d0134 100644
--- a/lib/libc/sys/fcntl.2
+++ b/lib/libc/sys/fcntl.2
@@ -352,28 +352,6 @@ This implementation detects that sleeping until a locked region is unlocked
 would cause a deadlock and fails with an
 .Er EDEADLK
 error.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn fcntl
-is implemented as the
-.Va fcntl
-syscall.
-.Pp
-In the threaded library, the
-.Va fcntl
-syscall is assembled to
-.Fn _thread_sys_fcntl
-and
-.Fn fcntl
-is implemented as a function which disables thread rescheduling, locks
-.Fa fd
-for read and write, then calls
-.Fn _thread_sys_fcntl .
-Before returning,
-.Fn fcntl
-unlocks
-.Fa fd
-and enables thread rescheduling.
 .Sh RETURN VALUES
 Upon successful completion, the value returned depends on
 .Fa cmd
diff --git a/lib/libc/sys/flock.2 b/lib/libc/sys/flock.2
index 33dcec5fff1e..f76b094450b8 100644
--- a/lib/libc/sys/flock.2
+++ b/lib/libc/sys/flock.2
@@ -112,27 +112,6 @@ forks and the child explicitly unlocks the file, the parent will
 lose its lock.
 .Pp
 Processes blocked awaiting a lock may be awakened by signals.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn flock
-is implemented as the
-.Va flock
-syscall.
-.Pp
-In the threaded library, the
-.Va flock
-syscall is assembled to
-.Fn _thread_sys_flock
-and
-.Fn flock
-is implemented as a function which locks
-.Fa fd
-for read and write, then calls
-.Fn _thread_sys_flock .
-Before returning,
-.Fn flock
-unlocks
-.Fa fd .
 .Sh RETURN VALUES
 .Rv -std flock
 .Sh ERRORS
diff --git a/lib/libc/sys/fsync.2 b/lib/libc/sys/fsync.2
index ac28aef172bc..821b09665d71 100644
--- a/lib/libc/sys/fsync.2
+++ b/lib/libc/sys/fsync.2
@@ -56,27 +56,6 @@ of buffers for the associated file to be written to a disk.
 should be used by programs that require a file to be
 in a known state, for example, in building a simple transaction
 facility.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn fsync
-is implemented as the
-.Va fsync
-syscall.
-.Pp
-In the threaded library, the
-.Va fsync
-syscall is assembled to
-.Fn _thread_sys_fsync
-and
-.Fn fsync
-is implemented as a function which locks
-.Fa fd
-for read and write, then calls
-.Fn _thread_sys_fsync .
-Before returning,
-.Fn fsync
-unlocks
-.Fa fd .
 .Sh RETURN VALUES
 .Rv -std fsync
 .Sh ERRORS
diff --git a/lib/libc/sys/getdirentries.2 b/lib/libc/sys/getdirentries.2
index 769ce32528d3..d5f073c8f3f1 100644
--- a/lib/libc/sys/getdirentries.2
+++ b/lib/libc/sys/getdirentries.2
@@ -141,27 +141,6 @@ a value returned in the location pointed to by
 .Pf ( Fn getdirentries
 only)
 or zero.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn getdirentries
-is implemented as the
-.Va getdirentries
-syscall.
-.Pp
-In the threaded library, the
-.Va getdirentries
-syscall is assembled to
-.Fn _thread_sys_getdirentries
-and
-.Fn getdirentries
-is implemented as a function which locks
-.Fa fd
-for read and write, then calls
-.Fn _thread_sys_getdirentries .
-Before returning,
-.Fn getdirentries
-unlocks
-.Fa fd .
 .Sh RETURN VALUES
 If successful, the number of bytes actually transferred is returned.
 Otherwise, -1 is returned and the global variable
diff --git a/lib/libc/sys/getpeername.2 b/lib/libc/sys/getpeername.2
index 8aa56254f881..7454550dd760 100644
--- a/lib/libc/sys/getpeername.2
+++ b/lib/libc/sys/getpeername.2
@@ -58,27 +58,6 @@ the amount of space pointed to by
 On return it contains the actual size of the name
 returned (in bytes).
 The name is truncated if the buffer provided is too small.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn getpeername
-is implemented as the
-.Va getpeername
-syscall.
-.Pp
-In the threaded library, the
-.Va getpeername
-syscall is assembled to
-.Fn _thread_sys_getpeername
-and
-.Fn getpeername
-is implemented as a function which locks
-.Fa s
-for read and write, then calls
-.Fn _thread_sys_getpeername .
-Before returning,
-.Fn getpeername
-unlocks
-.Fa s .
 .Sh RETURN VALUES
 .Rv -std getpeername
 .Sh ERRORS
diff --git a/lib/libc/sys/getsockname.2 b/lib/libc/sys/getsockname.2
index 5d0890d7989f..f4b30604b839 100644
--- a/lib/libc/sys/getsockname.2
+++ b/lib/libc/sys/getsockname.2
@@ -56,27 +56,6 @@ the amount of space pointed to by
 .Fa name .
 On return it contains the actual size of the name
 returned (in bytes).
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn getsockname
-is implemented as the
-.Va getsockname
-syscall.
-.Pp
-In the threaded library, the
-.Va getsockname
-syscall is assembled to
-.Fn _thread_sys_getsockname
-and
-.Fn getsockname
-is implemented as a function which locks
-.Fa fd
-for read and write, then calls
-.Fn _thread_sys_getsockname .
-Before returning,
-.Fn getsockname
-unlocks
-.Fa fd .
 .Sh RETURN VALUES
 .Rv -std getsockname
 .Sh ERRORS
diff --git a/lib/libc/sys/getsockopt.2 b/lib/libc/sys/getsockopt.2
index f570085f5f19..d932e1d30c8e 100644
--- a/lib/libc/sys/getsockopt.2
+++ b/lib/libc/sys/getsockopt.2
@@ -348,48 +348,6 @@ returns any pending error on the socket and clears
 the error status.
 It may be used to check for asynchronous errors on connected
 datagram sockets or for other asynchronous errors.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn getsockopt
-is implemented as the
-.Va getsockopt
-syscall.
-.Pp
-In the threaded library, the
-.Va getsockopt
-syscall is assembled to
-.Fn _thread_sys_getsockopt
-and
-.Fn getsockopt
-is implemented as a function which locks
-.Fa s
-for read and write, then calls
-.Fn _thread_sys_getsockopt .
-Before returning,
-.Fn getsockopt
-unlocks
-.Fa s .
-.Pp
-In the non-threaded library
-.Fn setsockopt
-is implemented as the
-.Va setsockopt
-syscall.
-.Pp
-In the threaded library, the
-.Va setsockopt
-syscall is assembled to
-.Fn _thread_sys_setsockopt
-and
-.Fn setsockopt
-is implemented as a function which locks
-.Fa s
-for read and write, then calls
-.Fn _thread_sys_setsockopt .
-Before returning,
-.Fn setsockopt
-unlocks
-.Fa s .
 .Sh RETURN VALUES
 .Rv -std
 .Sh ERRORS
diff --git a/lib/libc/sys/ioctl.2 b/lib/libc/sys/ioctl.2
index c16e12ef7368..c5e9a79d3a29 100644
--- a/lib/libc/sys/ioctl.2
+++ b/lib/libc/sys/ioctl.2
@@ -85,27 +85,6 @@ Macros and defines used in specifying an ioctl
 .Fa request
 are located in the file
 .Ao Pa sys/ioctl.h Ac .
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn ioctl
-is implemented as the
-.Va ioctl
-syscall.
-.Pp
-In the threaded library, the
-.Va ioctl
-syscall is assembled to
-.Fn _thread_sys_ioctl
-and
-.Fn ioctl
-is implemented as a function which locks
-.Va d
-for read and write, then calls
-.Fn _thread_sys_ioctl .
-Before returning,
-.Fn ioctl
-unlocks
-.Va d .
 .Sh RETURN VALUES
 If an error has occurred, a value of -1 is returned and
 .Va errno
diff --git a/lib/libc/sys/listen.2 b/lib/libc/sys/listen.2
index 1a976587a7a0..e245ad68b78f 100644
--- a/lib/libc/sys/listen.2
+++ b/lib/libc/sys/listen.2
@@ -85,27 +85,6 @@ or less than zero is specified,
 .Fa backlog
 is silently forced to
 .Va kern.ipc.somaxconn .
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn listen
-is implemented as the
-.Va listen
-syscall.
-.Pp
-In the threaded library, the
-.Va listen
-syscall is assembled to
-.Fn _thread_sys_listen
-and
-.Fn listen
-is implemented as a function which locks
-.Fa s
-for read and write, then calls
-.Fn _thread_sys_listen .
-Before returning,
-.Fn listen
-unlocks
-.Fa s .
 .Sh RETURN VALUES
 .Rv -std listen
 .Sh ERRORS
diff --git a/lib/libc/sys/open.2 b/lib/libc/sys/open.2
index 874ce7456dc3..2c8070b7873e 100644
--- a/lib/libc/sys/open.2
+++ b/lib/libc/sys/open.2
@@ -182,25 +182,6 @@ The system imposes a limit on the number of file descriptors
 open simultaneously by one process.
 .Xr Getdtablesize 2
 returns the current system limit.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn open
-is implemented as the
-.Va open
-syscall.
-.Pp
-In the threaded library, the
-.Va open
-syscall is assembled to
-.Fn _thread_sys_open
-and
-.Fn open
-is implemented as a function which disables thread rescheduling
-and calls
-.Fn _thread_sys_open .
-Before returning,
-.Fn open
-enables thread rescheduling.
 .Sh RETURN VALUES
 If successful,
 .Fn open
diff --git a/lib/libc/sys/read.2 b/lib/libc/sys/read.2
index e4f330aaeccb..42d04ce87337 100644
--- a/lib/libc/sys/read.2
+++ b/lib/libc/sys/read.2
@@ -116,54 +116,6 @@ return the number of bytes actually read and placed in the buffer.
 The system guarantees to read the number of bytes requested if
 the descriptor references a normal file that has that many bytes left
 before the end-of-file, but in no other case.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn read
-is implemented as the
-.Va read
-syscall.
-.Pp
-In the threaded library, the
-.Va read
-syscall is assembled to
-.Fn _thread_sys_read
-and
-.Fn read
-is implemented as a function which locks
-.Fa d
-for read, then calls
-.Fn _thread_sys_read .
-If the call to
-.Fn _thread_sys_read
-would block, a context switch is performed.
-Before returning,
-.Fn read
-unlocks
-.Fa d .
-.Pp
-In the non-threaded library
-.Fn readv
-is implemented as the
-.Va readv
-syscall.
-.Pp
-In the threaded library, the
-.Va readv
-syscall is assembled to
-.Fn _thread_sys_readv
-and
-.Fn readv
-is implemented as a function which locks
-.Fa d
-for read, then calls
-.Fn _thread_sys_readv .
-If the call to
-.Fn _thread_sys_readv
-would block, a context switch is performed.
-Before returning,
-.Fn readv
-unlocks
-.Fa d .
 .Sh RETURN VALUES
 If successful, the
 number of bytes actually read is returned.
diff --git a/lib/libc/sys/sendfile.2 b/lib/libc/sys/sendfile.2
index f073b067fccf..c2ca5296845c 100644
--- a/lib/libc/sys/sendfile.2
+++ b/lib/libc/sys/sendfile.2
@@ -104,33 +104,6 @@ The
 implementation of
 .Fn sendfile
 is "zero-copy", meaning that it has been optimized so that copying of the file data is avoided.
-.Pp
-In the non-threaded library
-.Fn sendfile
-is implemented as the
-.Va sendfile
-syscall.
-.Pp
-In the threaded library, the
-.Va sendfile
-syscall is assembled to
-.Fn _thread_sys_sendfile
-and
-.Fn sendfile
-is implemented as a function which locks
-.Fa fd
-for reading and
-.Fa s
-for writing, then calls
-.Fn _thread_sys_sendfile .
-If the call to
-.Fn _thread_sys_sendfile
-would block, a context switch is performed.  Before returning,
-.Fn sendfile
-unlocks
-.Fa fd
-and
-.Fa s .
 .Sh RETURN VALUES
 .Rv -std sendfile
 .Sh ERRORS
diff --git a/lib/libc/sys/write.2 b/lib/libc/sys/write.2
index 77fba35cd25a..d8a417756672 100644
--- a/lib/libc/sys/write.2
+++ b/lib/libc/sys/write.2
@@ -124,54 +124,6 @@ and
 may write fewer bytes than requested;
 the return value must be noted,
 and the remainder of the operation should be retried when possible.
-.Sh IMPLEMENTATION NOTES
-In the non-threaded library
-.Fn write
-is implemented as the
-.Va write
-syscall.
-.Pp
-In the threaded library, the
-.Va write
-syscall is assembled to
-.Fn _thread_sys_write
-and
-.Fn write
-is implemented as a function which locks
-.Fa d
-for read and write, then calls
-.Fn _thread_sys_write .
-If the call to
-.Fn _thread_sys_write
-would block, a context switch is performed.
-Before returning,
-.Fn write
-unlocks
-.Fa d .
-.Pp
-In the non-threaded library
-.Fn writev
-is implemented as the
-.Va writev
-syscall.
-.Pp
-In the threaded library, the
-.Va writev
-syscall is assembled to
-.Fn _thread_sys_writev
-and
-.Fn writev
-is implemented as a function which locks
-.Fa d
-for read and write, then calls
-.Fn _thread_sys_writev .
-If the call to
-.Fn _thread_sys_writev
-would block, a context switch is performed.
-Before returning,
-.Fn writev
-unlocks
-.Fa d .
 .Sh RETURN VALUES
 Upon successful completion the number of bytes which were written
 is returned.  Otherwise a -1 is returned and the global variable