Clarify the meaning of normal and subnormal.
diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst
index 0a1bfee..a3db956 100644
--- a/Doc/library/decimal.rst
+++ b/Doc/library/decimal.rst
@@ -548,8 +548,11 @@
.. method:: is_normal()
- Return :const:`True` if the argument is a *normal* finite number. Return
- :const:`False` if the argument is zero, subnormal, infinite or a NaN.
+ Return :const:`True` if the argument is a *normal* finite non-zero
+ number with an adjusted exponent greater than or equal to *Emin*.
+ Return :const:`False` if the argument is zero, subnormal, infinite or a
+ NaN. Note, the term *normal* is used here in a different sense with
+ the :meth:`normalize` method which is used to create canonical values.
.. versionadded:: 2.6
@@ -577,7 +580,8 @@
.. method:: is_subnormal()
Return :const:`True` if the argument is subnormal, and :const:`False`
- otherwise.
+ otherwise. A number is subnormal is if it is nonzero, finite, and has an
+ adjusted exponent less than *Emin*.
.. versionadded:: 2.6