# Version 60.0.0 "Are We Copies?" 2021-07-31
## New features and enhancements
* all: IETF BCP 47/RFC 5646 language tags: added support for language families
from ISO 639-5 that aren't part of 639-2.
* all: IETF BCP 47/RFC 5646 language tags: implemented support for Alpha 2
country codes of the "user-defined" category: `AA`, `QM`–`QZ`, `XA`–`XZ` and
* all: IETF BCP 47/RFC 5646 language tags: updated the various lists of valid
subtags from the official specs.
* MKVToolNix GUI: multiplexer: pressing the keyboard shortcut for the track's
"Language" label (Alt+L for English) will now open the language dialog.
* MKVToolNix GUI: multiplexer: added an option in the preferences for turning
off the colored boxes indicating which file each track belongs to.
## Bug fixes
* all: IETF BCP 47/RFC 5646 language tags: fixed validating extended language
& variant subtags against their allowed prefixes (e.g. a valid tag with a
country code as in `de-CH-1996` is recognized as valid while two generally
known variants that aren't allowed together as in `de-1901-1996` is
recognized as invalid).
* all: IETF BCP 47/RFC 5646 language tags: when looking up a language for a
two- or three-letter code, the programs will no longer compare that code
with language names as that was unintended, ambiguous (e.g. the code "Ga"
could be interpreted as the 639-2 alpha-2 code for "Irish" or as the name of
the language called "Ga") and only worked with languages whose name was at
most three letters long.
* mkvmerge: HEVC/H.265: appending Matroska files with HEVC tracks might lead
to the loss of the first couple of frames from each of the second and all
following files. Fixes #3170.
* mkvmerge, mkvextract: HEVC/H.265 parser: fixed the programs aborting when
parsing VPS or SPS NALUs with invalid content due to unhandled
exceptions. Fixes #3162.
* MKVToolNix GUI: multiplexer: when the option "use legacy MIME types for font
attachments" is enabled, the GUI will now use `application/x-truetype-font`
for font collection files.
* MKVToolNix GUI: multiplexer: fixed escaping the `mkvmerge` argument in the
"Show command-line options" dialog for the "Windows (cmd.exe)" mode. Fixes
* MKVToolNix GUI: multiplexer: when adding multiple files at once, the GUI
will sort file names with numbers the way a human would expect it to. For
example, `1.mp4`, `9.aac`, `10.srt`, `11.srt` are now sorted exactly that
order instead of `1.mp4`, `10.srt`, `11.srt`, `9.aac`.
* MKVToolNix GUI: header editor: the header editor will now honor the "use
legacy MIME types when adding font attachments" setting when adding new