-#define _PDCLIB_SIGABRT 6
-#define _PDCLIB_SIGFPE 8
-#define _PDCLIB_SIGILL 4
-#define _PDCLIB_SIGINT 2
-#define _PDCLIB_SIGSEGV 11
-#define _PDCLIB_SIGTERM 15
-
-/* The following should be defined to pointer values that could NEVER point to
- a valid function. (They are used as special arguments to signal().) Again, I
- took the values of my Linux box, which should be as good as any other value.
+#define _PDCLIB_ERANGE 1
+#define _PDCLIB_EDOM 2
+#define _PDCLIB_EILSEQ 3
+
+/* The following is not strictly "configuration", but there is no better place
+ to explain it than here.
+
+ PDCLib strives to be as generic as possible, so by default it does NOT define
+ any values beyond the three standard ones above, even where it would have
+ been prudent and convenient to do so. Any errno "caught" from the host OS,
+ and some internal error conditions as well, are all lumped together into the
+ value of '_PDCLIB_ERROR'.
+
+ '_PDCLIB_ERROR' is STRICLY meant as a PLACEHOLDER only.
+
+ You should NEVER ship an adaption of PDCLib still using that particular
+ value. You should NEVER write code that *tests* for that value. Indeed it is
+ not even conforming, since errno values should be defined as beginning with
+ an uppercase 'E', and there is no mechanics in <errno.h> to unmask that
+ particular value (for exactly that reason).
+
+ There also is no error message available for this value through either the
+ strerror() or perror() functions. It is being reported as "unknown" error.
+
+ The idea is that you scan the source of PDCLib for occurrences of this macro
+ and replace _PDCLIB_ERROR with whatever additional errno value you came up
+ with for your platform.
+
+ If you cannot find it within you to do that, tell your clients to check for
+ an errno value larger than zero. That, at least, would be standard compliant
+ (and fully portable).