We sometimes have questions about identity standards manuals, so some folks may find this interesting.
A copy of the New York Transit Authority Graphic Standards Manual, designed by Massimo Vignelli of Unimark International in 1970, was found recently and has been posted. Each page can be clicked for an enlargement, and you can roll over with your cursor to magnify further.
http://thestandardsmanual.com/grid.html
