The following variables are obsoleted in 2.0
- \plaintext_roff_command (was not used anymore)
-- \spell_command and \use_spell_lib (ispell support has been removed)
+
+- \personal_dictionary, \spell_command, \use_input_encoding,
+ \use_personal_dictionary and \use_spell_lib (ispell support has been
+ removed)
+
+- \spellchecker_use_alt_lang and \use_escape_chars (actually not used
+ by the UI, and it is as simple to check whether the relevant
+ variable is empty)
+
- \custom_export_command and \custom_export_format