How do I solve 28 across in Daily Telegraph Cryptic 31243?

Question

Accepted Answer

28 across reads "Open six deliveries, not just the last" (5 letters); the answer is OVERT. It's a letter-selection clue: take specific letters from a longer source. 'First of' means the opening letter, 'extremely' means first + last, 'regularly' means every other letter, 'oddly' / 'evenly' means odd or even positions. The full step-by-step breakdown is on this page.

Open six deliveries, not just the last (5)

28A — Open six deliveries, not just the last (5) — OVERT