Hi Vincent, word completion in calc is dfferent from writer.
CALC In calc choose Tools->CellContent--> AutoInput and make sure "autoinput" is ticked. In calc Autoinput == word completion. When completion is possible the text is highlighted and the tab key will toggle through some possible choices, the required entry is entered with "enter". WRITER In writer choose Tools-->Autocorrect/Autoformat-->Word Completion. There are various options to configure the behaviour, collect words etc. In HELP use "search" for word completion (not index) there are various options, shortcut keys etc. Please get the latest version and advise if any of these features are missing or may the bug be closed? Or did you mean to request that "tab" be added to the choices already in writer? thanks jim