Why choose ISO-8859-1 character set instead of using UTF8 in PuTTY?

Question

I have tried to do some research and I have to admit that I am clueless on this. If my question does not even make sense, I offer you my sincere apology for my ignorance.

PuTTY seems to use ISO-8859-1 character set by default. I had issues with common spanish chracters not displaying correctly so I changed it to UTF-8. Since I've done that, I have not had issues with displaying characters.

This might lead me to believe that the characters in ISO-8859-1 are just a subset of the UTF-8. However, I am fairly certain that it is not that simple but I still cannot get my head around it.

Please set me straight.

Answer 1

(I'm guessing. Send an email to sgtatham for the one true answer.)

The most likely reason for this default value is compatibility: Linux distributions used to use various ISO-8859 charsets for a long time before switching to en_US.UTF-8 as default. Other, older systems might not know UTF-8 at all. Some programs still don't work properly with multibyte input, even when built with ncursesw on Linux with UTF-8. Finally, it's so far impossible for the server to tell PuTTY what charset is being used.

(ISO-8859-* are indeed subsets of UTF-8, but not binary-compatible with it – only the first 128 bytes, ASCII, remain the same between various charsets.)

It is best to always set UTF-8 as default if you know that the server supports it.