etymology for some functions

Signed-off-by: Mattias Andrée <maandree@operamail.com>

16 files changed, 233 insertions, 5 deletions

diff --git a/doc/info/chap/error-reporting.texinfo b/doc/info/chap/error-reporting.texinfo
index 2a438e0..7059630 100644
--- a/doc/info/chap/error-reporting.texinfo
+++ b/doc/info/chap/error-reporting.texinfo
@@ -335,6 +335,13 @@ the @command{slibc}'s implementation will
 print the full process name, or more precisely,
 it prints @code{program_invocation_name}.
 
+@ifnottex
+Etymology: Print (warn)ing!
+@end ifnottex
+@iftex
+Etymology: Print @b{warn}ing!
+@end iftex
+
 @item void vwarn(const char* format, va_list args)
 @fnindex vwarn
 @hfindex err.h
@@ -345,6 +352,13 @@ the header file @file{<err.h>}. It is identical
 to @code{warn} except it uses @code{va_list}
 instead of being a variadic function.
 
+@ifnottex
+Etymology: (V)ariadic version of (`warn`).
+@end ifnottex
+@iftex
+Etymology: @b{V}ariadic version of @b{warn}.
+@end iftex
+
 @item void warnx(const char* format, ...)
 @fnindex warnx
 @hfindex err.h
@@ -355,6 +369,13 @@ the header file @file{<err.h>}. It is identical
 to @code{warn} except it does not print a
 description of the value of @code{errno}.
 
+@ifnottex
+Etymology: (`warn`), [x=](lesser variant).
+@end ifnottex
+@iftex
+Etymology: @b{warn}, [x=]@b{lesser variant}.
+@end iftex
+
 @item void vwarnx(const char* format, va_list args)
 @fnindex vwarnx
 @hfindex err.h
@@ -365,6 +386,13 @@ the header file @file{<err.h>}. It is identical
 to @code{warnx} except it uses @code{va_list}
 instead of being a variadic function.
 
+@ifnottex
+Etymology: (V)ariadic version of (`warnx`).
+@end ifnottex
+@iftex
+Etymology: @b{V}ariadic version of @b{warnx}.
+@end iftex
+
 @item noreturn void err(int status, const char* format, ...)
 @fnindex err
 @hfindex err.h
@@ -375,6 +403,13 @@ the header file @file{<err.h>}. It is identical
 to @code{warn} except will return with the
 exit value @code{status & 255}.
 
+@ifnottex
+Etymology: Report (err)or!
+@end ifnottex
+@iftex
+Etymology: Report @b{err}or!
+@end iftex
+
 @item noreturn void verr(int status, const char* format, va_list args)
 @fnindex verr
 @hfindex err.h
@@ -385,6 +420,13 @@ the header file @file{<err.h>}. It is identical
 to @code{err} except it uses @code{va_list}
 instead of being a variadic function.
 
+@ifnottex
+Etymology: (V)ariadic version of (`err`).
+@end ifnottex
+@iftex
+Etymology: @b{V}ariadic version of @b{err}.
+@end iftex
+
 @item noreturn void errx(int status, const char* format, ...)
 @fnindex errx
 @hfindex err.h
@@ -395,6 +437,13 @@ the header file @file{<err.h>}. It is identical
 to @code{err} except it does not print a
 description of the value of @code{errno}.
 
+@ifnottex
+Etymology: (`err`), [x=](lesser variant).
+@end ifnottex
+@iftex
+Etymology: @b{err}, [x=]@b{lesser variant}.
+@end iftex
+
 @item noreturn void verrx(int status, const char* format, va_list args)
 @fnindex verrx
 @hfindex err.h
@@ -405,6 +454,13 @@ the header file @file{<err.h>}. It is identical
 to @code{errx} except it uses @code{va_list}
 instead of being a variadic function.
 
+@ifnottex
+Etymology: (V)ariadic version of (`errx`).
+@end ifnottex
+@iftex
+Etymology: @b{V}ariadic version of @b{errx}.
+@end iftex
+
 @item void error(int status, int errnum, const char* format, ...)
 @fnindex error
 @hfindex error.h
diff --git a/doc/info/chap/language-facilities.texinfo b/doc/info/chap/language-facilities.texinfo
index 19cfec0..fe27446 100644
--- a/doc/info/chap/language-facilities.texinfo
+++ b/doc/info/chap/language-facilities.texinfo
@@ -356,6 +356,13 @@ The expression must not have said effects.
 must not be evaluated if @code{NDEBUG} is
 defined. If @code{NDEBUG} is defined,
 @code{assert} has no effect, but is defined.
+
+@ifnottex
+Etymology: (Assertion).
+@end ifnottex
+@iftex
+Etymology: @b{Assert}ion.
+@end iftex
 @end table
 
 If @command{slibc} extensions or GNU extensions
@@ -369,6 +376,13 @@ This macro is identical to @code{assert}, except
 the argument should be an error code, and a
 description of it is printed before the process
 exits. (Nothing happens if @code{errnum} is zero.)
+
+@ifnottex
+Etymology: (@code{assert}) version of (@code{perror}).
+@end ifnottex
+@iftex
+Etymology: @b{assert} version of @b{perror}.
+@end iftex
 @end table
 
 @fnindex static_assert
@@ -382,6 +396,13 @@ is included. @code{static_assert} is similar to
 the message to print if the assertion failed,
 and the assertion is evaluated at compile-time.
 
+@ifnottex
+Etymology: (Static) (assert)ion.
+@end ifnottex
+@iftex
+Etymology: @b{Static} @b{assert}ion.
+@end iftex
+
 Assertions should only be used to make sure that
 impossible conditions are not reached.
 
diff --git a/doc/info/chap/memory-allocation.texinfo b/doc/info/chap/memory-allocation.texinfo
index 20136b0..1b7c778 100644
--- a/doc/info/chap/memory-allocation.texinfo
+++ b/doc/info/chap/memory-allocation.texinfo
@@ -233,6 +233,13 @@ void function(size_t n)
 Both of these allocation-methods are both automatic
 and dynamic.
 
+@ifnottex
+Etymology: (Alloca)te!
+@end ifnottex
+@iftex
+Etymology: @b{Alloca}te!
+@end iftex
+
 @cpindex Memory exhaustion
 Memory allocation functions return @code{NULL} if
 the process cannot allocate more memory. However,
diff --git a/include/alloca.h b/include/alloca.h
index 010bb99..a800cf0 100644
--- a/include/alloca.h
+++ b/include/alloca.h
@@ -37,6 +37,8 @@
  * Undefined behaviour is invoked if the memory
  * cannot be allocated.
  * 
+ * @etymology  (Alloca)te!
+ * 
  * @param   size  The number of bytes to allocate.
  * @return        Pointer to the beginning of the allocated
  *                space. Do not free it, it will be freed
diff --git a/include/assert.h b/include/assert.h
index 12b20eb..4523860 100644
--- a/include/assert.h
+++ b/include/assert.h
@@ -35,6 +35,8 @@
  * POSIX specifies that `assert` shall not evaluate the
  * expression if `NDEBUG` is defined. This is probably
  * to save CPU-cycles.
+ * 
+ * @etymology  (Assert)ion.
  */
 #ifdef NDEBUG
 # define assert(expression)   ((void)0)
@@ -54,6 +56,8 @@
  * 
  * `assert_perror` is a GNU-compliant slibc extension.
  * 
+ * @etymology  (`assert`) version of (`perror`).
+ * 
  * @param  errnum:int  The error code, describing the error that occurred.
  */
 # ifdef assert_perror
@@ -84,6 +88,8 @@
  * A compile-time error should occur if the expression
  * evaluates to zero.
  * 
+ * @etymology  (Static) (assert)tion.
+ * 
  * @param  expression:scalar    The expression to evaluate.
  * @param  message:const char*  The message to print on error.
  */
diff --git a/include/ctype.h b/include/ctype.h
index 82f13af..9b6508c 100644
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -36,6 +36,8 @@
  * Check whether a character is an alphabetical
  * character or a decimal digit.
  * 
+ * @etymology  (Is) character either (al)phabetical or (num)erical [(al)pha(num)erical]?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in
  *             ['0', '9'], ['A', 'Z'], or ['a', 'z'].
@@ -51,6 +53,8 @@ int (isalnum)(int)  /* [0x30, 0x39], [0x41, 0x5A], [0x61, 0x7A] */
 /**
  * Check whether a character is an alphabetical character.
  * 
+ * @etymology  (Is) character (alpha)betical?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in
  *             ['A', 'Z'] or ['a', 'z'].
@@ -67,6 +71,8 @@ int (isalpha)(int)  /* [0x41, 0x5A], [0x61, 0x7A] */
  * 
  * This is a GNU extension.
  * 
+ * @etymology  (Is) character a (blank) space?
+ * 
  * @param   c  The character.
  * @return     Whether the character is a ' ' or a '\t'.
  */
@@ -83,6 +89,8 @@ int (isblank)(int) /* ' ', '\t' */
  * Check whether a character is a non-printable
  * ASCII character.
  * 
+ * @etymology  (Is) character a (c)o(ntr)o(l) character?
+ * 
  * @param   c  The character.
  * @return     Whether the character is lower than ' ',
  *             or is 0x7F.
@@ -98,6 +106,8 @@ int (iscntrl)(int)  /* [0x00, 0x1F], 0x7F */
 /**
  * Check whether a character is a decimal digit.
  * 
+ * @etymology  (Is) character a (digit)?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in ['0', '9'].
  */
@@ -109,6 +119,8 @@ int (isdigit)(int)  /* [0x30, 0x39] */
 /**
  * Check whether a character is has a printable glyph.
  * 
+ * @etymology  (Is) character (graph)ical?
+ * 
  * @param   c  The character.
  * @return     Whether the character is greater
  *             than ' ', but is not 0x7F.
@@ -122,6 +134,8 @@ int (isgraph)(int)  /* [0x21, 0x7E] */
  * Check whether a character is a lowercase
  * alphabetical character.
  * 
+ * @etymology  (Is) character a (lower)case character?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in ['a', 'z'].
  */
@@ -134,6 +148,8 @@ int (islower)(int)  /* [0x61, 0x7A] */
  * Check whether a character is has a printable glyph
  * or a blank space.
  * 
+ * @etymology  (Is) character (print)able?
+ * 
  * @param   c  The character.
  * @return     Whether the character is at least
  *             as great as ' ', but is not 0x7F.
@@ -148,6 +164,8 @@ int (isprint)(int)  /* [0x20, 0x7E] */
  * that is, a printable character but a blank space,
  * numerical or alphabetical.
  * 
+ * @etymology  (Is) character a (punct)uation?
+ * 
  * @param   c  The character.
  * @return     Whether the character is a punctuation.
  */
@@ -162,6 +180,8 @@ int (ispunct)(int)  /* isprint && !isalnum && !isspace */
 /**
  * Check whether a character is a whitespace character.
  * 
+ * @etymology  (Is) character white(space)?
+ * 
  * @param   c  The character.
  * @return     Whether the character is a ' ', '\f',
  *             '\n', '\r', '\t', or '\v'.
@@ -178,6 +198,8 @@ int (isspace)(int)  /* 0x20, [0x09, 0x0D] */
  * Check whether a character is an uppercase
  * alphabetical character.
  * 
+ * @etymology  (Is) character a (upper)case character?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in ['A', 'Z'].
  */
@@ -191,6 +213,8 @@ int (isupper)(int)  /* [0x41, 0x5A] */
  * hexadecimal digit. Both uppercase and
  * lowercase is supported.
  * 
+ * @etymology  (Is) character a he(x)adecimal digit?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in
  *             ['0', '9'], ['A', 'Z'], or ['a', 'z'].
@@ -208,11 +232,13 @@ int (isxdigit)(int)  /* [0x30, 0x39], [0x41, 0x46], [0x61, 0x66] */
  * Convert a uppercase ASCII character to
  * an lowercase ASCII character.
  * 
- * The function's behaviour is unspecifed
+ * The function's behaviour is unspecified
  * of the character is not alphabetical.
  * You should consider running
  * `(isupper(c) ? tolower(c) : c)` instead.
  * 
+ * @etymology  Convert character (to) (lower)case!
+ * 
  * @param   c  The character.
  * @return     The character in lowercase.
  *             Guaranteed to be unchanged if the
@@ -226,11 +252,13 @@ int (tolower)(int)  /* [0x41, 0x5A] -> [0x61, 0x7A] */
  * Convert a lowercase ASCII character to
  * an uppercase ASCII character.
  * 
- * The function's behaviour is unspecifed
+ * The function's behaviour is unspecified
  * of the character is not alphabetical.
  * You should consider running
  * `(isupper(c) ? tolower(c) : c)` instead.
  * 
+ * @etymology  Convert character (to) (upper)case!
+ * 
  * @param   c  The character.
  * @return     The character in uppercase.
  *             Guaranteed to be unchanged if the
@@ -245,6 +273,8 @@ int (toupper)(int)  /* [0x61, 0x7A] -> [0x41, 0x5A] */
 /**
  * Check whether a character is an ASCII character.
  * 
+ * @etymology  (Is) character an (ASCII) character?
+ * 
  * @param   c  The character
  * @return     Whether the character is an ASCII character.
  */
@@ -258,6 +288,12 @@ int (isascii)(int)  /* [0x00, 0x7E] */
  * Note that this does not make a proper character set
  * convertion and the result is virtually arbitrary.
  * 
+ * Justification for existence:
+ *   The highest bit has historically been used as a
+ *   parity bit.
+ * 
+ * @etymology  Truncate character (to) fit (ASCII) character set!
+ * 
  * @param   c  The character.
  * @return     The character with the 8:th bit cleared.
  */
@@ -290,6 +326,8 @@ int _toupper(int)
  * Check whether a character is an alphabetical
  * character or a decimal digit.
  * 
+ * @etymology  (Is) character (alpha)betical, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is
@@ -302,6 +340,8 @@ int isalnum_l(int, locale_t)
 /**
  * Check whether a character is an alphabetical character.
  * 
+ * @etymology  (Is) character (alpha)betical, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is alphabetical.
@@ -317,6 +357,8 @@ int isalpha_l(int, locale_t)
  * 
  * This is a GNU extension.
  * 
+ * @etymology  (Is) character a (blank) space, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is a ' ' or a '\t'.
@@ -330,6 +372,8 @@ int isblank_l(int, locale_t)
  * Check whether a character is a non-printable
  * ASCII character.
  * 
+ * @etymology  (Is) character a (c)o(ntr)o(l) character, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is non-printable.
@@ -341,6 +385,8 @@ int iscntrl_l(int, locale_t)
 /**
  * Check whether a character is a decimal digit.
  * 
+ * @etymology  (Is) character a (digit), with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is numerical.
@@ -352,6 +398,8 @@ int isdigit_l(int, locale_t)
 /**
  * Check whether a character is has a printable glyph.
  * 
+ * @etymology  (Is) character (graph)ical, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character has a glyph.
@@ -364,6 +412,8 @@ int isgraph_l(int, locale_t)
  * Check whether a character is a lowercase
  * alphabetical character.
  * 
+ * @etymology  (Is) character a (lower)case character, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is a lowercase letter.
@@ -376,6 +426,8 @@ int islower_l(int, locale_t)
  * Check whether a character is has a printable glyph
  * or a blank space.
  * 
+ * @etymology  (Is) character (print)able, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character has a printable
@@ -390,6 +442,8 @@ int isprint_l(int, locale_t)
  * that is, a printable character but a blank space,
  * numerical or alphabetical.
  * 
+ * @etymology  (Is) character a (punct)uation, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is a punctuation.
@@ -401,6 +455,8 @@ int ispunct_l(int, locale_t)
 /**
  * Check whether a character is a whitespace character.
  * 
+ * @etymology  (Is) character white(space), with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is a
@@ -414,6 +470,8 @@ int isspace_l(int, locale_t)
  * Check whether a character is an uppercase
  * alphabetical character.
  * 
+ * @etymology  (Is) character a (upper)case character, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is a uppercase letter.
@@ -427,6 +485,8 @@ int isupper_l(int, locale_t)
  * hexadecimal digit. Both uppercase and
  * lowercase is supported.
  * 
+ * @etymology  (Is) character a he(x)adecimal digit, with consideration for (l)ocale?
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          Whether the character is in
@@ -439,12 +499,14 @@ int isxdigit_l(int, locale_t)
 /**
  * Check whether a character is an ASCII character.
  * 
+ * @etymology  (Is) character an (ASCII) character, with consideration for (l)ocale?
+ * 
  * @param   c       The character
  * @param   locale  The locale.
  * @return          Whether the character is an ASCII character.
  */
 int isascii_l(int, locale_t)
-  __warning("This function is dangerous, use 'isascii_l' instead.")
+  __warning("This function is dangerous, use 'iswascii_l' instead.")
   __GCC_ONLY(__attribute__((__const__)));
 
 /**
@@ -453,6 +515,8 @@ int isascii_l(int, locale_t)
  * Note that this does not make a proper character set
  * convertion and the result is virtually arbitrary.
  * 
+ * @etymology  Truncate character (to) fit (ASCII) character set, with consideration for (l)ocale!
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          The character with the 8:th bit cleared.
@@ -471,6 +535,8 @@ int toascii_l(int, locale_t)
  * `(isupper_l(c, l) ? tolower_l(c, l) : c)`
  * instead.
  * 
+ * @etymology  Convert character (to) (lower)case, with consideration for (l)ocale!
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          The character in lowercase.
@@ -491,6 +557,8 @@ int tolower_l(int, locale_t)
  * `(isupper_l(c, l) ? tolower_l(c, l) : c)`
  * instead.
  * 
+ * @etymology  Convert character (to) (upper)case, with consideration for (l)ocale!
+ * 
  * @param   c       The character.
  * @param   locale  The locale.
  * @return          The character in uppercase.
diff --git a/include/err.h b/include/err.h
index a603cbb..63dcdda 100644
--- a/include/err.h
+++ b/include/err.h
@@ -37,6 +37,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  Print (warn)ing!
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
  */
@@ -49,6 +51,8 @@ void warn(const char*, ...)
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`warn`).
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
  */
@@ -60,6 +64,8 @@ void vwarn(const char*, va_list);
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (`warn`), [x=](lesser variant).
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
  */
@@ -72,6 +78,8 @@ void warnx(const char*, ...)
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`warnx`).
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
  */
@@ -83,6 +91,8 @@ void vwarnx(const char*, va_list);
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  Report (err)or!
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
@@ -96,6 +106,8 @@ __noreturn void err(int, const char*, ...)
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`err`).
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
@@ -108,6 +120,8 @@ __noreturn void verr(int, const char*, va_list);
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (`err`), [x=](lesser variant).
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
@@ -121,6 +135,8 @@ __noreturn void errx(int, const char*, ...)
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`errx`).
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
diff --git a/src/ctype.c b/src/ctype.c
index 3923def..a5eb75c 100644
--- a/src/ctype.c
+++ b/src/ctype.c
@@ -23,6 +23,8 @@
  * Check whether a character is an alphabetical
  * character or a decimal digit.
  * 
+ * @etymology  (Is) character either (al)phabetical or (num)erical [(al)pha(num)erical]?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in
  *             ['0', '9'], ['A', 'Z'], or ['a', 'z'].
@@ -36,6 +38,8 @@ int (isalnum)(int c)
 /**
  * Check whether a character is an alphabetical character.
  * 
+ * @etymology  (Is) character (alpha)betical?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in
  *             ['A', 'Z'] or ['a', 'z'].
@@ -50,6 +54,8 @@ int (isalpha)(int c)
  * Check whether a character is a regular blank space
  * or a horizontal tabulation.
  * 
+ * @etymology  (Is) character a (blank) space?
+ * 
  * @param   c  The character.
  * @return     Whether the character is a ' ' or a '\t'.
  */
@@ -63,6 +69,8 @@ int (isblank)(int c)
  * Check whether a character is a non-printable
  * ASCII character.
  * 
+ * @etymology  (Is) character a (c)o(ntr)o(l) character?
+ * 
  * @param   c  The character.
  * @return     Whether the character is lower than ' '.
  */
@@ -75,6 +83,8 @@ int (iscntrl)(int c)
 /**
  * Check whether a character is a decimal digit.
  * 
+ * @etymology  (Is) character a (digit)?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in ['0', '9'].
  */
@@ -87,6 +97,8 @@ int (isdigit)(int c)
 /**
  * Check whether a character is has a printable glyph.
  * 
+ * @etymology  (Is) character (graph)ical?
+ * 
  * @param   c  The character.
  * @return     Whether the character is greater than ' '.
  */
@@ -100,6 +112,8 @@ int (isgraph)(int c)
  * Check whether a character is a lowercase
  * alphabetical character.
  * 
+ * @etymology  (Is) character a (lower)case character?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in ['a', 'z'].
  */
@@ -113,6 +127,8 @@ int (islower)(int c)
  * Check whether a character is has a printable glyph
  * or a blank space.
  * 
+ * @etymology  (Is) character (print)able?
+ * 
  * @param   c  The character.
  * @return     Whether the character is at least
  *             as great as ' '.
@@ -128,6 +144,8 @@ int (isprint)(int c)
  * that is, a printable character but a blank space,
  * numerical or alphabetical.
  * 
+ * @etymology  (Is) character a (punct)uation?
+ * 
  * @param   c  The character.
  * @return     Whether the character is a punctuation.
  */
@@ -140,6 +158,8 @@ int (ispunct)(int c)
 /**
  * Check whether a character is a whitespace character.
  * 
+ * @etymology  (Is) character white(space)?
+ * 
  * @param   c  The character.
  * @return     Whether the character is a ' ', '\f',
  *             '\n', '\r', '\t', or '\v'.
@@ -154,6 +174,8 @@ int (isspace)(int c)
  * Check whether a character is an uppercase
  * alphabetical character.
  * 
+ * @etymology  (Is) character a (upper)case character?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in ['A', 'Z'].
  */
@@ -168,6 +190,8 @@ int (isupper)(int c)
  * hexadecimal digit. Both uppercase and
  * lowercase is supported.
  * 
+ * @etymology  (Is) character a he(x)adecimal digit?
+ * 
  * @param   c  The character.
  * @return     Whether the character is in
  *             ['0', '9'], ['A', 'Z'], or ['a', 'z'].
@@ -183,11 +207,13 @@ int (isxdigit)(int c)
  * Convert a uppercase ASCII character to
  * an lowercase ASCII character.
  * 
- * The function's behaviour is unspecifed
+ * The function's behaviour is unspecified
  * of the character is not alphabetical.
  * You should consider running
  * `(isupper(c) ? tolower(c) : c)` instead.
  * 
+ * @etymology  Convert character (to) (lower)case!
+ * 
  * @param   c  The character.
  * @return     The character in lowercase.
  *             Guaranteed to be unchanged if the
@@ -203,11 +229,13 @@ int (tolower)(int c)
  * Convert a lowercase ASCII character to
  * an uppercase ASCII character.
  * 
- * The function's behaviour is unspecifed
+ * The function's behaviour is unspecified
  * of the character is not alphabetical.
  * You should consider running
  * `(isupper(c) ? tolower(c) : c)` instead.
  * 
+ * @etymology  Convert character (to) (upper)case!
+ * 
  * @param   c  The character.
  * @return     The character in uppercase.
  *             Guaranteed to be unchanged if the
@@ -223,6 +251,8 @@ int (toupper)(int c)
 /**
  * Check whether a character is an ASCII character.
  * 
+ * @etymology  (Is) character an (ASCII) character?
+ * 
  * @param   c  The character
  * @return     Whether the character is an ASCII character.
  */
@@ -238,6 +268,12 @@ int (isascii)(int c)
  * Note that this does not make a proper character set
  * convertion and the result is virtually arbitrary.
  * 
+ * Justification for existence:
+ *   The highest bit has historically been used as a
+ *   parity bit.
+ * 
+ * @etymology  Truncate character (to) fit (ASCII) character set!
+ * 
  * @param   c  The character.
  * @return     The character with the 8:th bit cleared.
  */
diff --git a/src/err/err.c b/src/err/err.c
index 64062b8..d6d754a 100644
--- a/src/err/err.c
+++ b/src/err/err.c
@@ -26,6 +26,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  Report (err)or!
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
diff --git a/src/err/errx.c b/src/err/errx.c
index 07b4e2b..c8e11c9 100644
--- a/src/err/errx.c
+++ b/src/err/errx.c
@@ -26,6 +26,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (`err`), [x=](lesser variant).
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
diff --git a/src/err/verr.c b/src/err/verr.c
index f0fb3f7..f88d944 100644
--- a/src/err/verr.c
+++ b/src/err/verr.c
@@ -28,6 +28,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`err`).
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
diff --git a/src/err/verrx.c b/src/err/verrx.c
index ab30380..1c9e40c 100644
--- a/src/err/verrx.c
+++ b/src/err/verrx.c
@@ -27,6 +27,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`errx`).
+ * 
  * @parma  status  The exit status the process should have.
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
diff --git a/src/err/vwarn.c b/src/err/vwarn.c
index 43949e5..78676d4 100644
--- a/src/err/vwarn.c
+++ b/src/err/vwarn.c
@@ -26,6 +26,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`warn`).
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
  */
diff --git a/src/err/vwarnx.c b/src/err/vwarnx.c
index 594dfc7..c44e57a 100644
--- a/src/err/vwarnx.c
+++ b/src/err/vwarnx.c
@@ -25,6 +25,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (V)ariadic version of (`warnx`).
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  args    Formatting-arguments.
  */
diff --git a/src/err/warn.c b/src/err/warn.c
index ea5aacb..de5c793 100644
--- a/src/err/warn.c
+++ b/src/err/warn.c
@@ -26,6 +26,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  Print (warn)ing!
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
  */
diff --git a/src/err/warnx.c b/src/err/warnx.c
index 835044a..d80dfd8 100644
--- a/src/err/warnx.c
+++ b/src/err/warnx.c
@@ -26,6 +26,8 @@
  * 
  * This is a non-standard BSD extension.
  * 
+ * @etymology  (`warn`), [x=](lesser variant).
+ * 
  * @param  format  Formatting-string for the warning.
  * @param  ...     Formatting-arguments.
  */