AM Stereo

Initially adopted by many commercial AM broadcasters in the mid to late 1980s, AM stereo broadcasting soon began to decline due to a lack of receivers (most "AM/FM stereo" radios only receive FM in stereo), a growing exodus of music broadcasters to FM, concentration of ownership of the few remaining stations in the hands of large corporations and the removal of music from AM stations in favour of news/talk or sports broadcasting. By 2001, most of the former AM stereo broadcasters were no longer stereo or had left the AM band entirely. (https://en.wikipedia.org/wiki/AM_stereo)

Dolby C

Dolby C noise reduction was a very common feature on mid to high-end cassette decks, not on portable devices. It further reduces background hiss, beyond Dolby B levels. To playback a Dolby C encoded recording, you need a device that can decode it for the best audio quality.

Girly

Pinky walkman models ideal for girls.

Glamour Boys

Glorious, glamorous, luxurious, and especially golden walkmans. The glamour boys have it all under control.

I'am so blockhead!

A little bit too rectangles?

Louder

Walkmans with built-in speaker, to spread the music wider!

Open else

Walkmans which doors opening differently, unusually.

Pioneers

They showed the path to everyone.

Stretchy

Look, I can stretch!

Transparent

Just to be clear, do you see me? Transparent models.

Wireless

Wireless headphones were all the rage! Keep the Walkman in your pocket or bag, no cables to snag. Most models are from the Sony Wireless series, while others might by produced by Sony for Casio for instance.