diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index af0c55c65..9cf67ee6f 100644
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -31,22 +31,7 @@ system_data_types \- overview of system data types
 .\" Layout:
 .\"	A list of type names (the struct/union keyword will be omitted).
 .\"	Each entry will have the following parts:
-.\"		* Include
-.\"			The headers will be in the following order:
-.\"			1) The main header that shall define the type
-.\"			   according to the C Standard,
-.\"			   and
-.\"			   the main header that shall define the type
-.\"			   according to POSIX,
-.\"			   in alphabetical order.
-.\"			;
-.\"			2) All other headers that shall define the type
-.\"			   as described in the previous header(s)
-.\"			   according to the C Standard or POSIX,
-.\"			   in alphabetical order.
-.\"			*) All headers that define the type
-.\"			   *if* the type is not defined by C nor POSIX,
-.\"			   in alphabetical order.
+.\"		* Include (see NOTES)
 .\"
 .\"		* Definition (no "Definition" header)
 .\"			Only struct/union types will have definition;
@@ -55,9 +40,10 @@ system_data_types \- overview of system data types
 .\"		* Description (no "Description" header)
 .\"			A few lines describing the type.
 .\"
-.\"		* Conforming to
+.\"		* Bugs (if any)
+.\"
+.\"		* Conforming to (see NOTES)
 .\"			Format: CXY and later; POSIX.1-XXXX and later.
-.\"			Forget about pre-C99 C standards (i.e., C89/C90)
 .\"
 .\"		* Notes (optional)
 .\"
@@ -203,8 +189,8 @@ See also:
 .RS
 .br
 Include:
-.IR <stdio.h> ;
-or
+.IR <stdio.h> .
+Alternatively,
 .IR <wchar.h> .
 .PP
 An object type used for streams.
@@ -269,19 +255,14 @@ type in this page.
 .RS
 .br
 Include:
-.IR <sys/types.h> ;
-or
-.I <grp.h>
-or
-.I <pwd.h>
-or
-.I <signal.h>
-or
-.I <stropts.h>
-or
-.I <sys/ipc.h>
-or
-.I <sys/stat.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <grp.h> ,
+.IR <pwd.h> ,
+.IR <signal.h> ,
+.IR <stropts.h> ,
+.IR <sys/ipc.h> ,
+.IR <sys/stat.h> ,
 or
 .IR <unistd.h> .
 .PP
@@ -306,8 +287,8 @@ See also:
 .RS
 .br
 Include:
-.IR <sys/types.h> ;
-or
+.IR <sys/types.h> .
+Alternatively,
 .IR <sys/resource.h> .
 .PP
 A type used to hold a general identifier.
@@ -586,29 +567,19 @@ See also:
 .RS
 .br
 Include
-.IR <sys/types.h> ;
-or
-.I <fcntl.h>
-or
-.I <sched.h>
-or
-.I <signal.h>
-or
-.I <spawn.h>
-or
-.I <sys/msg.h>
-or
-.I <sys/sem.h>
-or
-.I <sys/shm.h>
-or
-.I <sys/wait.h>
-or
-.I <termios.h>
-or
-.I <time.h>
-or
-.I <unistd.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <fcntl.h> ,
+.IR <sched.h> ,
+.IR <signal.h> ,
+.IR <spawn.h> ,
+.IR <sys/msg.h> ,
+.IR <sys/sem.h> ,
+.IR <sys/shm.h> ,
+.IR <sys/wait.h> ,
+.IR <termios.h> ,
+.IR <time.h> ,
+.IR <unistd.h> ,
 or
 .IR <utmpx.h> .
 .PP
@@ -738,11 +709,10 @@ types in this page.
 .RS
 .br
 Include:
-.IR <signal.h> ;
-or
-.I <aio.h>
-or
-.I <mqueue.h>
+.IR <signal.h> .
+Alternatively,
+.IR <aio.h> ,
+.IR <mqueue.h> ,
 or
 .IR <time.h> .
 .PP
@@ -787,8 +757,8 @@ structure in this page.
 .RS
 .br
 Include:
-.IR <signal.h> ;
-or
+.IR <signal.h> .
+Alternatively,
 .IR <sys/wait.h> .
 .PP
 .EX
@@ -823,9 +793,9 @@ See also:
 .RS
 .br
 Include:
-.IR <signal.h> ;
-or
-.I <spawn.h>
+.IR <signal.h> .
+Alternatively,
+.IR <spawn.h> ,
 or
 .IR <sys/select.h> .
 .PP
@@ -886,55 +856,32 @@ in this page.
 Include:
 .I <stddef.h>
 or
-.IR <sys/types.h> ;
-or
-.I <aio.h>
-or
-.I <glob.h>
-or
-.I <grp.h>
-or
-.I <iconv.h>
-or
-.I <monetary.h>
-or
-.I <mqueue.h>
-or
-.I <ndbm.h>
-or
-.I <pwd.h>
-or
-.I <regex.h>
-or
-.I <search.h>
-or
-.I <signal.h>
-or
-.I <stdio.h>
-or
-.I <stdlib.h>
-or
-.I <string.h>
-or
-.I <strings.h>
-or
-.I <sys/mman.h>
-or
-.I <sys/msg.h>
-or
-.I <sys/sem.h>
-or
-.I <sys/shm.h>
-or
-.I <sys/socket.h>
-or
-.I <sys/uio.h>
-or
-.I <time.h>
-or
-.I <unistd.h>
-or
-.I <wchar.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <aio.h> ,
+.IR <glob.h> ,
+.IR <grp.h> ,
+.IR <iconv.h> ,
+.IR <monetary.h> ,
+.IR <mqueue.h> ,
+.IR <ndbm.h> ,
+.IR <pwd.h> ,
+.IR <regex.h> ,
+.IR <search.h> ,
+.IR <signal.h> ,
+.IR <stdio.h> ,
+.IR <stdlib.h> ,
+.IR <string.h> ,
+.IR <strings.h> ,
+.IR <sys/mman.h> ,
+.IR <sys/msg.h> ,
+.IR <sys/sem.h> ,
+.IR <sys/shm.h> ,
+.IR <sys/socket.h> ,
+.IR <sys/uio.h> ,
+.IR <time.h> ,
+.IR <unistd.h> ,
+.IR <wchar.h> ,
 or
 .IR <wordexp.h> .
 .PP
@@ -1007,21 +954,15 @@ types in this page.
 .RS
 .br
 Include:
-.IR <sys/types.h> ;
-or
-.I <aio.h>
-or
-.I <monetary.h>
-or
-.I <mqueue.h>
-or
-.I <stdio.h>
-or
-.I <sys/msg.h>
-or
-.I <sys/socket.h>
-or
-.I <sys/uio.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <aio.h> ,
+.IR <monetary.h> ,
+.IR <mqueue.h> ,
+.IR <stdio.h> ,
+.IR <sys/msg.h> ,
+.IR <sys/socket.h> ,
+.IR <sys/uio.h> ,
 or
 .IR <unistd.h> .
 .PP
@@ -1083,9 +1024,9 @@ types in this page.
 .RS
 .br
 Include:
-.IR <sys/types.h> ;
-or
-.I <sys/select.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <sys/select.h> ,
 or
 .IR <sys/time.h> .
 .PP
@@ -1110,23 +1051,17 @@ structure in this page.
 .RS
 .br
 Include:
-.I <sys/types.h>
-or
-.IR <time.h> ;
-or
-.I <sched.h>
-or
-.I <sys/msg.h>
-or
-.I <sys/select.h>
-or
-.I <sys/sem.h>
-or
-.I <sys/shm.h>
-or
-.I <sys/stat.h>
+.I <time.h>
 or
-.I <sys/time.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <sched.h> ,
+.IR <sys/msg.h> ,
+.IR <sys/select.h> ,
+.IR <sys/sem.h> ,
+.IR <sys/shm.h> ,
+.IR <sys/stat.h> ,
+.IR <sys/time.h> ,
 or
 .IR <utime.h> .
 .PP
@@ -1153,8 +1088,8 @@ See also:
 .RS
 .br
 Include:
-.IR <sys/types.h> ;
-or
+.IR <sys/types.h> .
+Alternatively,
 .IR <time.h> .
 .PP
 Used for timer ID returned by
@@ -1176,17 +1111,13 @@ See also:
 .RS
 .br
 Include:
-.IR <time.h> ;
-or
-.I <aio.h>
-or
-.I <mqueue.h>
-or
-.I <sched.h>
-or
-.I <signal.h>
-or
-.I <sys/select.h>
+.IR <time.h> .
+Alternatively,
+.IR <aio.h> ,
+.IR <mqueue.h> ,
+.IR <sched.h> ,
+.IR <signal.h> ,
+.IR <sys/select.h> ,
 or
 .IR <sys/stat.h> .
 .PP
@@ -1214,11 +1145,10 @@ See also:
 .RS
 .br
 Include:
-.IR <sys/time.h> ;
-or
-.I <sys/resource.h>
-or
-.I <sys/select.h>
+.IR <sys/time.h> .
+Alternatively,
+.IR <sys/resource.h> ,
+.IR <sys/select.h> ,
 or
 .IR <utmpx.h> .
 .PP
@@ -1247,17 +1177,13 @@ See also:
 .RS
 .br
 Include:
-.IR <sys/types.h> ;
-or
-.I <pwd.h>
-or
-.I <signal.h>
-or
-.I <stropts.h>
-or
-.I <sys/ipc.h>
-or
-.I <sys/stat.h>
+.IR <sys/types.h> .
+Alternatively,
+.IR <pwd.h> ,
+.IR <signal.h> ,
+.IR <stropts.h> ,
+.IR <sys/ipc.h> ,
+.IR <sys/stat.h> ,
 or
 .IR <unistd.h> .
 .PP
@@ -1418,9 +1344,9 @@ types in this page.
 .RS
 .br
 Include:
-.IR <stdarg> ;
-or
-.I <stdio.h>
+.IR <stdarg> .
+Alternatively,
+.IR <stdio.h> ,
 or
 .IR <wchar.h> .
 .PP
@@ -1473,6 +1399,16 @@ If the type has upper and lower limits,
 the user should check that the value is within those limits,
 before actually copying the value.
 The example below shows how these conversions should be done.
+.SS Conventions used in this page
+In "Conforming to" we only concern ourselves with
+C99 and later and POSIX.1-2001 and later.
+Some types may be specified in earlier versions of one of these standards,
+but in the interests of simplicity we omit details from earlier standards.
+.PP
+In "Include", we first note the "primary" header(s) that
+define the type according to either the C or POSIX.1 standards.
+Under "Alternatively", we note additional headers that
+the standards specify shall define the type.
 .SH EXAMPLES
 The program shown below scans from a string and prints a value stored in
 a variable of an integer type that doesn't have a length modifier.
