The nonprinting characters feature is used to determine if redundant or unwanted
nonprinting characters appear in the document. It currently shows spaces as
nonprinting characters. In my opinion, a single space is in fact a printed
character, even though it technically consists of zero pixels. Therefore, I
propose an option that single spaces _not_ be marked when showing nonprinting
character. However, multiple spaces should in fact be shown when displaying
nonprinting characters so that their presence can be dealt with.

I understand that spaces are in fact a special corner case, which is why I
suggest that this feature be optional, not mandatory.

Thanks.