It's amazing what you can encode in various formats.
To encode a character in this scheme, we first convert its ASCII code to binary. The binary representation of "u" is 01110101. We can see that the positions of the 1's are 0, 2, 3, and 6. Therefore, to encode the secret word, we italicize the first, third, fourth, and seventh words.
Some smaller bands used this to record audio in 90s home studios because it was really cost effective. I believe Fektion Fekler [1] used this for their album From Here To Heaven.
The Sony PCM-F1 was one of these - and was the first time I got confused between "is this live or is this the playback?" because until then it had been obvious.
https://www.youtube.com/watch?v=TUS0Zv2APjU