In the opening titles of each episode, the letters on the Fawlty Towers sign began to go missing and then in later episodes rearranged into partial anagrams of Fawlty Towers. Almost every other Fawlty Towers website has them, so here they are…
Episode Seven: Communication Problems. The "L" hanging down, "S" missing (exactly the same as episode two).
Episode Eight: The Psychiatrist. A young boy is seen tampering with the sign as the episode begins, then he moves away to reveal "Watery Fowls"
Episode Nine: Waldorf Salad. The letters have been rearranged to spell "Flay Otters"
Episode Ten: The Kipper and The Corpse. The letters have been rearranged to spell "Fatty Owls"
Episode Eleven: The Anniversary. The letters have been rearranged to spell "Flowery Twats". At last, a true anagram of Fawlty Towers! It is surprising they got this one past the broadcasting censors. If you don't know what I'm talking about, go look up twats. In a dictionary.
Episode Twelve: Basil The Rat. The letters have been rearranged to spell "Farty Towels"