Use greek characters once available
In const char* const SI_PREFIX[]={"y","z","a","f","p","n","u","m"," ","k","M","G","T","P","E","Z","Y"};
Fix the micro unit u to mu, which it should be according to the SI standard. This is a problem of
character encoding. Many schemes like ASCII or EBCDIC support u but not the Greek character mu. Since we are
using the system default character encoding scheme it is likely that u is supported. In the future, if switching
away from c-strings and system-based character endcoding it should be considered to use an encoding that supports the Greek character mu and to then properly implement it in the SI-prefix list.