document disabling of encode guards
diff --git a/README.md b/README.md
index 1a01b42..906bf41 100644
--- a/README.md
+++ b/README.md
@@ -230,9 +230,9 @@
 
     |               | smallest | largest |  
     |---------------|----------|---------|
-    | encode only   |      900 |    2100 |
-    | decode only   |     2800 |   13500 |
-    | combined      |     3700 |   15600 |
+    | encode only   |      850 |    2100 |
+    | decode only   |     2900 |   13500 |
+    | combined      |     3750 |   15600 |
     
  From the table above, one can see that the amount of code pulled in
  from the QCBOR library varies a lot, ranging from 1KB to 15KB.  The
@@ -271,11 +271,10 @@
  carefully written to be defensive.
 
  Disable features with defines like
- QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA (saves about 400 bytes) and
+ QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA (saves about 400 bytes) 
+ QCBOR_DISABLE_ENCODE_USAGE_GUARDS (saves about 150), and
  QCBOR_DISABLE_PREFERRED_FLOAT (saves about 900 bytes).  More of these
- defines are planned than are currently implemented (they are a little
- complex to implement because all the combination configurations must
- be tested).
+ defines are planned than are currently implemented.
  
  If QCBOR is installed as a shared library, then of course only one
  copy of the code is in memory no matter how many applications use it.
diff --git a/inc/qcbor/qcbor_encode.h b/inc/qcbor/qcbor_encode.h
index ae5027a..54a3635 100644
--- a/inc/qcbor/qcbor_encode.h
+++ b/inc/qcbor/qcbor_encode.h
@@ -229,6 +229,19 @@
  [RFC 8742] (https://tools.ietf.org/html/rfc8742). This encoder supports
  either just by whether the first item added is an array, map or other.
 
+ If QCBOR is compiled with QCBOR_DISABLE_ENCODE_USAGE_GUARDS defined,
+ the errors QCBOR_ERR_CLOSE_MISMATCH, QCBOR_ERR_ARRAY_TOO_LONG,
+ QCBOR_ERR_TOO_MANY_CLOSES, QCBOR_ERR_ARRAY_OR_MAP_STILL_OPEN, and
+ QCBOR_ERR_ENCODE_UNSUPPORTED will never be returned. It is up to the
+ caller to make sure that opened maps, arrays and byte-string wrapping
+ is closed correctly and that QCBOREncode_AddType7() is called
+ correctly.  With this defined, it is easier to make a mistake when
+ authoring the encoding of a protocol that will output not well formed
+ CBOR, but as long as the calling code is correct, it is safe to
+ disable these checks. Bounds checking that prevents security issues
+ in the code is still enforced. This define reduces the size of
+ encoding object code by about 150 bytes.
+
  @anchor Tags-Overview
 
  ## Tags Overview