There are (maybe not explicitly designated as such, but en-space or em-space would be reasonable, I think). The problem is that there's no sane or consistent w

There are (maybe not explicitly designated as such, but en-space or em-space would be reasonable, I think). The problem is that there's no sane or consistent way to actually input these characters (besides perhaps a macro that detects double-spaces and replaces them with a single somewhat-longer-than-normal space).