Lossy compressors don't have the same constraints as a lossless compressor. If you data your input, compress it, and then decompress it, the output is not identical to the input. This allows the compressor to potentially compress the data far more than even the ideal lossless compressor hypothesized above.
The question mark (?), also known as the interrogation point, query, and eroteme, is a punctuation mark that indicates an interrogative clause, or phrase in many languages. The question mark is not used for indirect questions.
It is also commonly known as the pound sign. In Canada the symbol is called both the number sign and the pound sign. The American company Avaya have an option in their programming to denote Canadian English, which in turn instructs the system to say number sign to callers instead of pound sign.