nl_langinfo(3): document recognized item names

While here, remove .Tn macro usage (prompted by mandoc lint).

PR:		251468
Reviewed by:	bapt
Differential Revision:	https://reviews.freebsd.org/D27606

lib/libc/locale/nl_langinfo.3

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 30, 2012
+.Dd December 14, 2020
 .Dt NL_LANGINFO 3
 .Os
 .Sh NAME
@@ -46,10 +46,6 @@ the particular language or cultural area defined in the program or thread's
 locale, or in the case of
 .Fn nl_langinfo_l ,
 the locale passed as the second argument.
-The manifest constant names and values of
-.Fa item
-are defined in
-.In langinfo.h .
 .Pp
 Calls to
 .Fn setlocale
@@ -59,12 +55,102 @@ or to the
 category
 .Dv LC_ALL ,
 may overwrite the buffer pointed to by the return value.
+.Pp
+The manifest constant names and values of
+.Fa item
+are defined in
+.In langinfo.h .
+.Pp
+The following standard constants are recognized:
+.Bl -column "Constant" "Category"
+.It Sy Constant Ta Sy Category Ta Sy Description
+.It Dv CODESET Ta Dv LC_CTYPE Ta codeset name
+.It Dv D_T_FMT Ta Dv LC_TIME Ta string for formatting date and time
+.It Dv D_FMT Ta Dv LC_TIME Ta date format string
+.It Dv T_FMT Ta Dv LC_TIME Ta time format string
+.It Dv T_FMT_AMPM Ta Dv LC_TIME Ta a.m. or p.m. time format string
+.It Dv AM_STR Ta Dv LC_TIME Ta ante-meridiem affix
+.It Dv PM_STR Ta Dv LC_TIME Ta post-meridiem affix
+.It Dv DAY_1 Ta Dv LC_TIME Ta name of the first day of the week
+.It Dv DAY_2 Ta Dv LC_TIME Ta name of the second day of the week
+.It Dv DAY_3 Ta Dv LC_TIME Ta name of the third day of the week
+.It Dv DAY_4 Ta Dv LC_TIME Ta name of the fourth day of the week
+.It Dv DAY_5 Ta Dv LC_TIME Ta name of the fifth day of the week
+.It Dv DAY_6 Ta Dv LC_TIME Ta name of the sixth day of the week
+.It Dv DAY_7 Ta Dv LC_TIME Ta name of the seventh day of the week
+.It Dv ABDAY_1 Ta Dv LC_TIME Ta abbreviated name of the first day of the week
+.It Dv ABDAY_2 Ta Dv LC_TIME Ta abbreviated name of the second day of the week
+.It Dv ABDAY_3 Ta Dv LC_TIME Ta abbreviated name of the third day of the week
+.It Dv ABDAY_4 Ta Dv LC_TIME Ta abbreviated name of the fourth day of the week
+.It Dv ABDAY_5 Ta Dv LC_TIME Ta abbreviated name of the fifth day of the week
+.It Dv ABDAY_6 Ta Dv LC_TIME Ta abbreviated name of the sixth day of the week
+.It Dv ABDAY_7 Ta Dv LC_TIME Ta abbreviated name of the seventh day of the week
+.It Dv MON_1 Ta Dv LC_TIME Ta name of the first month of the year
+.It Dv MON_2 Ta Dv LC_TIME Ta name of the second month
+.It Dv MON_3 Ta Dv LC_TIME Ta name of the third month
+.It Dv MON_4 Ta Dv LC_TIME Ta name of the fourth month
+.It Dv MON_5 Ta Dv LC_TIME Ta name of the fifth month
+.It Dv MON_6 Ta Dv LC_TIME Ta name of the sixth month
+.It Dv MON_7 Ta Dv LC_TIME Ta name of the seventh month
+.It Dv MON_8 Ta Dv LC_TIME Ta name of the eighth month
+.It Dv MON_9 Ta Dv LC_TIME Ta name of the ninth month
+.It Dv MON_10 Ta Dv LC_TIME Ta name of the tenth month
+.It Dv MON_11 Ta Dv LC_TIME Ta name of the eleventh month
+.It Dv MON_12 Ta Dv LC_TIME Ta name of the twelfth month
+.It Dv ABMON_1 Ta Dv LC_TIME Ta abbreviated name of the first month
+.It Dv ABMON_2 Ta Dv LC_TIME Ta abbreviated name of the second month
+.It Dv ABMON_3 Ta Dv LC_TIME Ta abbreviated name of the third month
+.It Dv ABMON_4 Ta Dv LC_TIME Ta abbreviated name of the fourth month
+.It Dv ABMON_5 Ta Dv LC_TIME Ta abbreviated name of the fifth month
+.It Dv ABMON_6 Ta Dv LC_TIME Ta abbreviated name of the sixth month
+.It Dv ABMON_7 Ta Dv LC_TIME Ta abbreviated name of the seventh month
+.It Dv ABMON_8 Ta Dv LC_TIME Ta abbreviated name of the eighth month
+.It Dv ABMON_9 Ta Dv LC_TIME Ta abbreviated name of the ninth month
+.It Dv ABMON_10 Ta Dv LC_TIME Ta abbreviated name of the tenth month
+.It Dv ABMON_11 Ta Dv LC_TIME Ta abbreviated name of the eleventh month
+.It Dv ABMON_12 Ta Dv LC_TIME Ta abbreviated name of the twelfth month
+.It Dv ERA Ta Dv LC_TIME Ta era description segments
+.It Dv ERA_D_FMT Ta Dv LC_TIME Ta era date format string
+.It Dv ERA_D_T_FMT Ta Dv LC_TIME Ta era date and time format string
+.It Dv ERA_T_FMT Ta Dv LC_TIME Ta era time format string
+.It Dv ALT_DIGITS Ta Dv LC_TIME Ta alternative symbols for digits
+.It Dv RADIXCHAR Ta Dv LC_NUMERIC Ta radix character
+.It Dv THOUSEP Ta Dv LC_NUMERIC Ta separator for thousands
+.It Dv YESEXPR Ta Dv LC_MESSAGES Ta affirmative response extended regular
+expression
+.It Dv NOEXPR Ta Dv LC_MESSAGES Ta negative response extended regular expression
+.It Dv CRNCYSTR Ta Dv LC_MONETARY Ta local currency symbol, preceded by '-' if the
+symbol should appear before the value, '+' if the symbol should appear after the
+value, or '.' if the symbol should replace the radix character; if the local
+currency symbol is the empty string, implementations may return the empty string
+.Pq Qq
+.El
+.Pp
+The following non-standard
+.Fx
+extensions are recognized:
+.Bl -column "Constant" "Category"
+.It Sy Constant Ta Sy Category Ta Sy Description
+.It Dv D_MD_ORDER Ta Dv LC_TIME Ta month/day order
+.It Dv ALTMON_1 Ta Dv LC_TIME Ta standalone name of the first month
+.It Dv ALTMON_2 Ta Dv LC_TIME Ta standalone name of the second month
+.It Dv ALTMON_3 Ta Dv LC_TIME Ta standalone name of the third month
+.It Dv ALTMON_4 Ta Dv LC_TIME Ta standalone name of the fourth month
+.It Dv ALTMON_5 Ta Dv LC_TIME Ta standalone name of the fifth month
+.It Dv ALTMON_6 Ta Dv LC_TIME Ta standalone name of the sixth month
+.It Dv ALTMON_7 Ta Dv LC_TIME Ta standalone name of the seventh month
+.It Dv ALTMON_8 Ta Dv LC_TIME Ta standalone name of the eighth month
+.It Dv ALTMON_9 Ta Dv LC_TIME Ta standalone name of the ninth month
+.It Dv ALTMON_10 Ta Dv LC_TIME Ta standalone name of the tenth month
+.It Dv ALTMON_11 Ta Dv LC_TIME Ta standalone name of the eleventh month
+.It Dv ALTMON_12 Ta Dv LC_TIME Ta standalone name of the twelfth month
+.It Dv YESSTR Ta Dv LC_MESSAGES Ta affirmative response string
+.It Dv NOSTR Ta Dv LC_MESSAGES Ta negative response string
+.El
 .Sh RETURN VALUES
 In a locale where langinfo data is not defined,
 .Fn nl_langinfo
-returns a pointer to the corresponding string in the
-.Tn POSIX
-locale.
+returns a pointer to the corresponding string in the POSIX locale.
 .Fn nl_langinfo_l
 returns the same values as
 .Fn nl_langinfo .