In my dictionary some words are marked with αρχαιοπρεπής (dated, archaic), λόγιος (learned form) and παλαιότερα (more ancient use). What are the differences, if any, between these terms, and what is their relation to Katharevousa? Can these four categories be used interchangeably?
Also, is it possible that some words from Katharevousa, e.g. αποστολεύς, are not to be used in Modern Greek (even in a proper context) but that the use of a declination of the word, e.g. του αποστολέως, would be acceptable in the proper context?
Basically, when does Katharevousa ends and when do so-called learned words begin?