Base 65536
<i>Base65536 uses only "safe" Unicode code points - no unassigned code points, no whitespace, no control characters, etc..</i><p><i>The string encodes two bytes per code point.</i><p>Is it really 64k then? It is hard to understand how this works without documentation on the format.<p>I wonder how many others were able to mentally decode the example input string just on sight, from having worked with ASCII extensively.