Complex sentence: Many of these managers were appointed as caretaker managers prior to being given a permanent position; if so this is denoted in the "Caretaker appointment" column, if not then the column is left blank.
Split into simpler sentences: Many of these managers were appointed as caretaker managers prior to being given a permanent position. If so, this is denoted in the "Caretaker appointment" column; if not, then the column is left blank.