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+
+Don't use memcmp.  Use {tor,fast}_{memeq,memneq,memcmp}.
+
+Don't use assert.  Use tor_assert or tor_assert_nonfatal or BUG.  Prefer
+nonfatal assertions or BUG()s.
+
+Don't use sprintf or snprintf.  Use tor_asprintf or tor_snprintf.
+
+Don't write hand-written binary parsers.  Use trunnel.
+
+Don't use malloc, realloc, calloc, free, strdup, etc. Use tor_malloc,
+tor_realloc, tor_calloc, tor_free, tor_strdup, etc.
+
+Don't use tor_realloc(x, y\*z). Use tor_reallocarray(x, y, z);
+
+Don't say "if (x) foo_free(x)".  Just foo_free(x) and make sure that
+foo_free(NULL) is a no-op.
+
+Don't use toupper or tolower; use TOR_TOUPPER and TOR_TOLOWER.
+
+Don't use isalpha, isalnum, etc.  Instead use TOR_ISALPHA, TOR_ISALNUM, etc.
+
+Don't use strcat, strcpy, strncat, or strncpy. Use strlcat and strlcpy
+instead.
+
+Don't use tor_asprintf then smartlist_add; use smartlist_add_asprintf.
+
+Don't use any of these functions: they aren't portable. Use the
+version prefixed with `tor_` instead: strtok_r, memmem, memstr,
+asprintf, localtime_r, gmtime_r, inet_aton, inet_ntop, inet_pton,
+getpass, ntohll, htonll, strdup,   (This list is incomplete.)
+
+Don't create or close sockets directly. Instead use the wrappers in
+compat.h.
+
+When creating new APIs, only use 'char \*' to represent 'pointer to a
+nul-terminated string'.  Represent 'pointer to a chunk of memory' as
+'uint8_t \*'.  (Many older Tor APIs ignore this rule.)
+
+Don't encode/decode u32, u64, or u16 to byte arrays by casting
+pointers. That can crash if the pointers aren't aligned, and can cause
+endianness problems.  Instead say something more like set_uint32(ptr,
+htonl(foo)) to encode, and ntohl(get_uint32(ptr)) to decode.
+
+Don't declare a 0-argument function with "void foo()".  That's C++
+syntax. In C you say "void foo(void)".
+
+When creating new APIs, use const everywhere you reasonably can.
+
+Sockets should have type tor_socket_t, not int.
+