==================
.. note::
The ASDF Standard is at v1.6.0
- Add ``yaml_tag_handles`` property to allow definition of custom yaml
``%TAG`` handles in the asdf file header. [`963 <https://github.com/asdf-format/asdf/issues/963>`_]
- Add new resource mapping API for extending asdf with additional
schemas. [`819 <https://github.com/asdf-format/asdf/issues/819>`_, `#828 <https://github.com/asdf-format/asdf/issues/828>`_, `#843 <https://github.com/asdf-format/asdf/issues/843>`_, `#846 <https://github.com/asdf-format/asdf/issues/846>`_]
- Add global configuration mechanism. [`819 <https://github.com/asdf-format/asdf/issues/819>`_, `#839 <https://github.com/asdf-format/asdf/issues/839>`_, `#844 <https://github.com/asdf-format/asdf/issues/844>`_, `#847 <https://github.com/asdf-format/asdf/issues/847>`_]
- Drop support for automatic serialization of subclass
attributes. [`825 <https://github.com/asdf-format/asdf/issues/825>`_]
- Support asdf:// as a URI scheme. [`854 <https://github.com/asdf-format/asdf/issues/854>`_, `#855 <https://github.com/asdf-format/asdf/issues/855>`_]
- Include only extensions used during serialization in
a file's metadata. [`848 <https://github.com/asdf-format/asdf/issues/848>`_, `#864 <https://github.com/asdf-format/asdf/issues/864>`_]
- Drop support for Python 3.5. [`856 <https://github.com/asdf-format/asdf/issues/856>`_]
- Add new extension API to support versioned extensions.
[`850 <https://github.com/asdf-format/asdf/issues/850>`_, `#851 <https://github.com/asdf-format/asdf/issues/851>`_, `#853 <https://github.com/asdf-format/asdf/issues/853>`_, `#857 <https://github.com/asdf-format/asdf/issues/857>`_, `#874 <https://github.com/asdf-format/asdf/issues/874>`_]
- Permit wildcard in tag validator URIs. [`858 <https://github.com/asdf-format/asdf/issues/858>`_, `#865 <https://github.com/asdf-format/asdf/issues/865>`_]
- Implement support for ASDF Standard 1.6.0. This version of
the standard limits mapping keys to string, integer, or
boolean. [`866 <https://github.com/asdf-format/asdf/issues/866>`_]
- Stop removing schema defaults for all ASDF Standard versions,
and automatically fill defaults only for versions <= 1.5.0. [`860 <https://github.com/asdf-format/asdf/issues/860>`_]
- Stop removing keys with ``None`` values from the tree on write. This
fixes a long-standing issue where the tree structure is not preserved
on write, but will break ``ExtensionType`` subclasses that depend on
this behavior. Extension developers will need to modify their
``to_tree`` methods to check for ``None`` before adding a key to
the tree (or modify the schema to permit nulls, if that is the
intention). [`863 <https://github.com/asdf-format/asdf/issues/863>`_]
- Deprecated the ``auto_inline`` argument to ``AsdfFile.write_to`` and
``AsdfFile.update`` and added ``AsdfConfig.array_inline_threshold``. [`882 <https://github.com/asdf-format/asdf/issues/882>`_, `#991 <https://github.com/asdf-format/asdf/issues/991>`_]
- Add ``edit`` subcommand to asdftool for efficient editing of
the YAML portion of an ASDF file. [`873 <https://github.com/asdf-format/asdf/issues/873>`_, `#922 <https://github.com/asdf-format/asdf/issues/922>`_]
- Increase limit on integer literals to signed 64-bit. [`894 <https://github.com/asdf-format/asdf/issues/894>`_]
- Remove the ``asdf.test`` method and ``asdf.__githash__`` attribute. [`943 <https://github.com/asdf-format/asdf/issues/943>`_]
- Add support for custom compression via extensions. [`931 <https://github.com/asdf-format/asdf/issues/931>`_]
- Remove unnecessary ``.tree`` from search result paths. [`954 <https://github.com/asdf-format/asdf/issues/954>`_]
- Drop support for bugs in older operating systems and Python versions. [`955 <https://github.com/asdf-format/asdf/issues/955>`_]
- Add argument to ``asdftool diff`` that ignores tree nodes that match
a JMESPath expression. [`956 <https://github.com/asdf-format/asdf/issues/956>`_]
- Fix behavior of ``exception`` argument to ``GenericFile.seek_until``. [`980 <https://github.com/asdf-format/asdf/issues/980>`_]
- Fix issues in file type detection to allow non-seekable input and
filenames without recognizable extensions. Remove the ``asdf.asdf.is_asdf_file``
function. [`978 <https://github.com/asdf-format/asdf/issues/978>`_]
- Update ``asdftool extensions`` and ``asdftool tags`` to incorporate
the new extension API. [`988 <https://github.com/asdf-format/asdf/issues/988>`_]
- Add ``AsdfSearchResult.replace`` method for assigning new values to
search results. [`981 <https://github.com/asdf-format/asdf/issues/981>`_]
- Search for block index starting from end of file. Fixes rare bug when
a data block contains a block index. [`990 <https://github.com/asdf-format/asdf/issues/990>`_]
- Update asdf-standard to 1.6.0 tag. [`993 <https://github.com/asdf-format/asdf/issues/993>`_]