They shouldn't show as visual representations, but some "ASCII" charts show the IBM PC character set instead of the ASCII set. IIRC, up to 0xFF UTF-8 and 8859 are very close with the exceptions being the UTF-8 escapes for the longer characters.

Opera AI solved the problem:

If you want to use symbols for Mars and Venus for example,they are not in range(0,0x20). They are in Miscellanous Symbols block.