Cryptic crossword No 3,421

Hi Gennaro, thanks for this puzzle which I found to be a trickier challenge than normal - but only reflects my solving skills because after revealing a few clues the wordplay was immediately clear and no less fair or accurate than usual. Favourites included 11a, 14a, 17a, 27a, 5d, 17d & 20d. Cheers!

Aha! Finally found the hidden directive, very nicely done Gennaro. Top picks 9a, 26a, 1d, 3d, 7d, 23d, thank you