Each dash separates a unique player. So in "RC-RF-R" the actions went: the first player raised, then the second player 3-bet, then the third player 4-bet, followed by the first player calling, and finally the current action is the second player folding to the 4-bet
All folds are ignored unless they're the current action. R-F could have several players folding in between. Essentially R-F-F-F and R-F-F will both turn into R-F internally