The facts on the fax – from ABC News

"These documents do not appear to have been the result of technology that was available in 1972 and 1973," said Bill Flynn, one of country's top authorities on document authentication. "The cumulative evidence that's available … indicates that these documents were produced on a computer, not a typewriter:" Among the points Flynn and other experts noted:

1.) The memos were written using a proportional typeface, where letters take up variable space according to their size, rather than fixed-pitch typeface used on typewriters, where each letter is allotted the same space. Proportional typefaces are available only on computers or on very high-end typewriters that were unlikely to be used by the National Guard.
2.) The memos include superscript, i.e. the "th" in "187th" appears above the line in a smaller font. Superscript was not available on typewriters.
3.) The memos included "curly" apostrophes rather than straight apostrophes found on typewriters.
4.) The font used in the memos is Times Roman, which was in use for printing but not in typewriters. The Haas Atlas — the bible of fonts — does not list Times Roman as an available font for typewriters.
5.) The vertical spacing used in the memos, measured at 13 points, was not available in typewriters, and only became possible with the advent of computers.

CBS has no choice: they must reveal the source of these (apparently) forged documents.

Update – according to the Kerry Spot, CBS is “very confident” the memos are genuine. Hmmmm…