Self-reference
Ever since Epimenides the Cretan (7th century B.C.) declared that All Cretans are liars, the notion of self-reference became synonymous (and often erroneously) with that of paradox. However, most ubiquitous self-reference which happens each time somebody says "I", is harmless. Following are a few gems from Metamagical Themas.

  1. Thit sentence is not self-referential because "thit" is not a word.
  2. If this sentence didn't exist, somebody would have invented it.
  3. This is not a complete. Sentence. This either.
  4. This sentence will end before you can say "Jack Rob
  5. Does this sentence remind you of Agatha Cristie?

Raymond Smullyan lists what he calls self-annihilating sentences from a collection by Saul Gorn "S. Gorn's Compendium of Rarely Used Cliches." :

  1. Before I begin speaking, there is something I would like to say.
  2. I am a firm believer in optimism because without optimism, what else is there?
  3. Half the lies they tell about me are true.
  4. Every Tom, Dick, and Harry is called John.
  5. Having lost sight of our goal, we must redouble our efforts!
  6. I'll see to it that your project deserves to be funded.
  7. I've given you an unlimited budget, and you have already exceeded it!
  8. A preposition must never be used to end a sentence with.
  9. This species has always been extinct.
  10. Authorized parking forbidden!
  11. If you're not prejudiced, you just don't understand!
  12. Inflation is an economic device whereby each person earns more than the next.
  13. Superstition brings bad luck.
  14. That's a real step forward into the unknown.
  15. You've outdone yourself as usual.
  16. Every once in a while it never stops raining.
  17. Monism is the theory that anything less than everything is nothing.
  18. A formalist is one who cannot understand a theory unless it is meaningless.

How many mistakes are there in the sentence: 'This sentance contanes one misteak'? What is the answer to the same question for this sentence: 'Their are three misteaks in this sentence'?

From the wonderful Beyond Numeracy I gleaned the following two pearls

  1. There is the case of the voter who when asked by a pollster what were the reasons for the ignorance and apathy of the American public, responded, "I don't know and I don't care."
  2. What is the question that contains the word cantaloupe for no apparent reason?

Lest you form a self-defeating impression that thinking up self-referential sentences is an exclusive pastime of self-indulgent mathematicians, I'll cite from a small book by William Safire

  1. Don't use contractions in formal writing.
  2. Do not put statements in the negative form.
  3. Avoid run-on sentences they are hard to read.
  4. Verbs has to agree with their subjects.
  5. Avoid trandy locutions that sound flaky.

A subtlety from the Littlewood's Miscellany:

E.Harrison: "Is it true that philosophy has never proved that something exists?" Bertrand Russell: "Yes, and the evidence for it is purely empirical."

The following comes from A Whack on The Side of The Head by R. von Oech

Every rule here can be challenged except this one.