-The adventure.text file is no longer required at runtime. Instead, it
-is compiled at build time to a source module containing C structures,
-which is then linked to the advent binary.
+The adventure.text file is no longer required at runtime. Instead, an
+adventure.yaml file is compiled at build time to a source module
+containing C structures, which is then linked to the advent
+binary. The YAML is drastically easier to read and edit than
+the old ad-hoc format of adventure.txt.
+
+The game-save format has changed. This was done to simplify the
+FORTRAN-derived code that formerly implemented the save/restore
+functions; without C's fread(3)/fwrite() and structs it was
+necessarily pretty ugly by modern standards. Encryption and
+checksumming have been discarded - it's pointless to try
+tamper-proofing saves when everyone has the source code.