22.4.4 String construction on Windows systems

When LispWorks for Windows starts up on a OS with a non-Latin-1 code page, it calls

so that by default, newly constructed strings can contain the data likely to be returned from the OS or user input.

If you know your string only needs to contain 8-bit data, then you can create it explicitly with element type base-char .

Conversely if you know that a string may need to contain 16-bit data even on a Latin-1 code page system, then you should create it explicitly with element-type simple-char.