11001 ----- memcpy (heap.pvvs)
11010 ----- memrand (heap.pvvs)
11011 ----- memcmp (heap.pvvs)
+ 11100 ----- memsrch (heap.pvvs)
100xxx - unassigned
101xxx - unassigned
110xxx - conversion functions
00001000 xxxxxxxx - for use by 1000
00001001 xxxxxxxx - for use by 1001
...etc
+
+Also by convention, functions which return a pointer will use the value `0` to
+represent a `NULL` pointer.