Some clarifications.
diff --git a/Misc/SpecialBuilds.txt b/Misc/SpecialBuilds.txt
index 0851aa5..0507c6e 100644
--- a/Misc/SpecialBuilds.txt
+++ b/Misc/SpecialBuilds.txt
@@ -80,7 +80,9 @@
8 bytes are added at each end of each block of N bytes requested. The
memory layout is like so, where p represents the address returned by a
-malloc-like or realloc-like function:
+malloc-like or realloc-like function (p[i:j] means the slice of bytes
+from *(p+i) inclusive up to *(p+j) exclusive; note that the treatment
+of negative indices differs from a Python slice):
p[-8:-4]
Number of bytes originally asked for. 4-byte unsigned integer,
@@ -104,7 +106,9 @@
4-byte unsigned integer, big-endian.
If "bad memory" is detected later, the serial number gives an
excellent way to set a breakpoint on the next run, to capture the
- instant at which this block was passed out.
+ instant at which this block was passed out. The static function
+ bumpserialno() in obmalloc.c is the only place the serial number
+ is incremented, and exists so you can set such a breakpoint easily.
A malloc-like or free-like function first checks that the FORBIDDENBYTEs
at each end are intact. If they've been altered, diagnostic output is
@@ -124,7 +128,9 @@
This is what is generally meant by "a debug build" of Python.
Py_DEBUG implies Py_REF_DEBUG, Py_TRACE_REFS, and PYMALLOC_DEBUG (if
-WITH_PYMALLOC is enabled).
+WITH_PYMALLOC is enabled). In addition, C assert()s are enabled (via
+the C way: by not defining NDEBUG), and some routines do additional
+sanity checks inside "#ifdef Py_DEBUG" blocks.
---------------------------------------------------------------------------
COUNT_ALLOCS