So, having started to play with the early build of the YDKJ SRF extractor and started to notice a few things. Firstly, the very first version of the YDKJ game engine attempts to make it harder to use the SRF sound content for certain files by changing the Apple codec id to YDKJ (for the record, it should be ima4, as these are Apple IMA ADPCM files). Not to difficult to work around. The other thing is that the question pack ‘upgrade’ actually censors part of the game. With the standard warning that all of the files in question, and the explanation of what occurs contains offensive material, you can make the comparison yourself at The Cutting Room Floor.
Many of the other titles have this easter egg in a clean form, but the code to trigger it is different for the foreign langauge editions, obviously.