+* Automatic decoding of :ref:`DEFINED BY <definedby>` fields
+* Ability to know exact decoded field presence, emptiness: for example
+ ``SEQUENCE`` can lack ``OPTIONAL SEQUENCE OF`` field, but also can
+ have it with no elements inside
+* **Strict** DER-encoding checks. If whole input binary is parsed, then
+ it must be completely valid DER-encoded structure
+* Ability to allow BER-encoded data with knowing if any of specified
+ field has either DER or BER encoding (or possibly indefinite-length
+ encoding). For example
+ `CMS <https://en.wikipedia.org/wiki/Cryptographic_Message_Syntax>`__
+ structures allow BER encoding for the whole message, except for
+ ``SignedAttributes`` -- you can easily verify your CMS satisfies that
+ requirement
+* Extensive and comprehensive
+ `hypothesis <https://hypothesis.readthedocs.io/en/master/>`__
+ driven tests coverage. It also has been fuzzed with
+ `python-afl <http://jwilk.net/software/python-afl>`__
+* Some kind of strong typing: SEQUENCEs require the exact **type** of
+ settable values, even when they are inherited (assigning ``Integer``
+ to the field with the type ``CMSVersion(Integer)`` is not allowed)
+* However they do not require exact tags matching: IMPLICIT/EXPLICIT
+ tags will be set automatically in the given sequence (assigning of
+ ``CMSVersion()`` object to the field ``CMSVersion(expl=...)`` will
+ automatically set required tags)
+* Descriptive errors, like ``pyderasn.DecodeError: UTCTime
+ (tbsCertificate:validity:notAfter:utcTime) (at 328) invalid UTCTime format``
+* ``__slots__``, ``copy.copy()`` friendliness
+* Workability with ``pickle``
+* `Cython <https://cython.org/>`__ compatibility
+* Could be significantly :ref:`faster <performance>` and have lower memory usage
+* :ref:`Pretty printer <pprinting>` and
+ :ref:`command-line decoder <cmdline>`, that could