What you’re seeing is just a comment which sometimes is incorrect (i.e. garbage). The actual keyboard code ZBrush uses is within the square brackets [ … ] Some are direct ASCII equivalents but it depends on your keyboard.
The key code will vary depending on your keyboard layout, so your “Delete” key won’t necessarily be the same as mine. For example, the Tilde key, which is supposed to scroll the canvas in wrap mode, won’t work for me and I have to use the @ key instead.
You can find the key code for a specific key by pressing a key and looking at the Preferences>Utilities>View Keyboad Status slider. Note that using a Modifier key will add that to the result:
Shift = 256
Ctrl = 512
Alt = 1024
And pressing the Modifiers on their own will likely add to the previous value. For example, pressing the Spacebar and then the Shift key will probably give you 288. (The Spacebar is 32.)