What does the cryptic crossword clue "Naughty ad by telephone not acceptable (6,3,4)" mean?

The wordplay uses an anagram. anagram of AD + BY + TELEPHONE = BEYONDTHEPALE The answer is BEYONDTHEPALE.

Naughty ad by telephone not acceptable (6,3,4)

Independent Cryptic #1819 | 14 Across | 2025-01-05 flower