+* Compatibility with older documents/layouts
+
+LyX 2.0.x uses an external python script, lyx2lyx, to import documents
+written using previous versions of LyX. All versions of LyX as far back as
+0.10 are supported.
+
+Of course, this means that you must have python (>= 2.3.4, <3)
+installed in order to use LyX 2.0.x with your old documents.
+
+lyx2lyx also has the framework in place to be able to convert documents to an
+earlier format (which requires python 2.3.4 at least). However, these
+converters have only been written for the conversion from 2.0.x to 1.6.x,
+1.5.x, 1.4.x and 1.3.x, so versions of LyX older than 1.3.0 will NOT be able to
+read documents saved with LyX 2.0.x. The conversion from 2.0.x to 1.6.x-1.3.x
+is lossless as long as no new features are used. lyx2lyx tries hard to find
+something equivalent for new features such as boxes, but this is known to fail
+sometimes. LyX 1.6.9 contains an updated lyx2lyx that can read documents in
+2.0.x format.
+
+Furthermore, LyX uses a converter layout2layout.py, also written in python
+that will convert old layout files on the fly. You can also call it manually
+on your layout files if you want to convert them to 2.0.x format permanently.
+
+* Formatted references
+
+Before version 2.0, LyX used the LaTeX package "prettyref" to produce
+"formatted references", such as "Section 2.1". This package has several
+shortcomings when used in a non-English environment, not least of which is
+that it has no mechanism for internationalization. (See bug #6421 and those
+it references.)
+
+As of LyX 2.0, users can choose whether to use prettyref or, alternatively,
+the "refstyle" package. The current version of refstyle, v0.5, ships with
+translations for several languages and provides an easy mechanism for users
+to translate the references it produces into still other languages. It also
+defines many more commands than prettyref does, including, for example, ones
+to produce "ranges", such as "Sections 2.1 to 2.3". Some LyX developers are
+already working with the refstyle maintainer, Danie Els, to make it work more
+easily with LyX and to extend the translations it provides. (You are invited
+to contribute translations, too!)
+
+Because many LyX users already have customized prettyref for their purposes,
+LyX 1.6.x files opened in LyX 2.0 will continue to use prettref by default.
+New LyX 2.0 files will use refstyle by default. Both can of course be changed
+in Document>Settings. Please be advised, however, that prettyref support is to
+be considered deprecated: It may well be removed in LyX 2.1, and all users are
+encouraged to adapt their layout files, etc, to refstyle.
+
+Doing so is fairly simple. With prettyref, one has declarations such as:
+ \newrefformat{for}(Formula \ref{#1}}
+The refstyle equivalent is:
+ \newref{for}{refcmd={Formula \ref{#1}}}
+The translation is obviously trivial.
+
+* Preparing for Unicode:
+
+As of version 1.5.0, LyX uses Unicode internally. This is a major change that
+affects documents and layouts likewise. We have tried to do out best to make the
+transition as smooth as possible for you. However, there are some caveats:
+
+- User layout files must be converted to UTF-8
+
+ In versions prior to 1.5.0, layout styles were allowed to use non-ASCII names
+ using the local encodings. LyX-1.5 and later assume that all layout files are
+ UTF-8 encoded. This means that non-ASCII style names are still allowed
+ but they must be valid UTF-8 strings. One way of doing the conversion
+ is to use iconv. Using bash, the script below should work:
+
+ #! /bin/sh
+
+ cd /path/to/layouts
+ for l in *
+ do
+ cp "$l" tmp.txt
+ iconv -f latin1 -t utf8 tmp.txt -o "$l"
+ done
+ rm -f tmp.txt
+
+- Inset encodings and Conversion from earlier LyX versions
+
+ As part of the transition to unicode, lyx2lyx (the scripts used for
+ converting back and forth between different versions of the lyx
+ files) converts old .lyx files, which may use a number of different
+ encodings, to UTF-8. This conversion depends on correctly
+ identifying the language of the text. There were previously some
+ edge-cases (insets embedded in different-language text type
+ scenarios) in which the language was incorrectly identified, which
+ caused some text to appear incorrectly after having upgraded from
+ older versions. This has now been fixed. Unfortunately, however, the
+ fix cannot be applied to files which have already been converted
+ past format 249. So if you have already converted your old files
+ (using a development version or release candidate), this fix won't
+ help, unless you still have the originals lying around (and haven't
+ yet made too many changes to the newer versions ;) ).
+
+Generally, it is probably wise to keep a backup of the old version of your
+files, at least until you are sure that the upgrade went smoothly (which it
+almost always will).
+
+* Languages/encodings and insets
+
+One of the bugs fixed in LyX 1.5.0 is that previously, there were certain
+specific cases in which the LaTeX generated did not correctly reflect
+language/encoding transitions in and around insets (footnotes, LyX notes).
+After much deliberation, it was decided not to change older files such that
+they will still reflect the old LaTeX output; rather, they will now correctly
+reflect the situation as it appears in the GUI. This means, however, that if
+you mangled the text in the GUI in the older versions, in order that it
+generate the correct LaTeX output, the LaTeX will now generate the mangled
+text. If this is problematic for you, please get in touch with us on the
+developers mailing list, we do have some possible solutions for this.
+
+The effects of this will be more pronounced for RTL (Hebrew, Arabic, Farsi)
+users -- though they affect users of other languages as well.
+
+* Floatflt in 1.2.x and older
+
+If you were previously (in LyX 1.1.x) using the floatflt paragraph
+option to wrap text around a figure, it was necessary to modify this
+for LyX 1.2.0 manually, as described in the manuals. The feature has
+been re-implemented as "Floating figure" inset in 1.3.0. Old files will
+be converted automatically, but you may want to convert the
+1.2.x-style ERT constructs with the native solution (see section 3.8
+of the Extended Features manual).
+
+* Babel changes since 1.2.x
+
+Since LyX 1.2.0, the babel package is loaded after the user-defined