Solid or spaced em dash? Also, in three below, I've seen the spaced en dash used in lieu of the em dash itself. Is this acceptable? What's your preference below — 1, 2 or 3? (1) Because the data had not been fully analyzed—let alone collated—the publication of the report was delayed. (2) Because the data had not been fully analyzed — let alone collated — the publication of the report was delayed. (3) Because the data had not been fully analyzed – let alone collated – the publication of the report was delayed. Hyphens used? I've seen this: Because the data had not been fully analyzed--let alone collated--the publication of the report was delayed. (Horrible, IMO.) And this: Because the data had not been fully analyzed -- let alone collated -- the publication of the report was delayed. (Not good either.) Thank you.
Spacing is a stylistic choice. Many guides say no spaces, but the AP style guide doesn't prefer one over the other. Regarding the other issues, look over the Wiki page on dashes. It's very helpful.
Either is acceptable, there is no standard. 1 is the most common I've seen in US English by far. I prefer 1 aesthetically. The double hyphen versions are aggressively tacky looking.
i prefer and recommend no space... a double hyphen is only meant to be used in the ms, to indicate an em dash is wanted there... the reason being that it leaves no doubt that an em dash is wanted, since some fonts' em dashes are hard to distinguish from a hyphen... nowhere would a double hyphen be acceptable other than in the ms...
