What does the cryptic crossword clue "Railing if cooking bad at Rules (10)" mean?

The definition is "Railing". The wordplay uses an anagram. anagram of BAD + AT + RULES = BALUSTRADE; definition: "Railing" The answer is BALUSTRADE.

Railing if cooking bad at Rules (10)

Independent Cryptic #11663 | 23 Across | 2024-02-27 flower