Thought this may help some folks collecting old MTG cards like myself.
PS...not my article. (taken from http://magic.oshkoshmagic.com)

Revised Edition & Unlimited Edition

Revised (3rd Edition) and Unlimited Edition cards are rather similar, but have a few key differences that set them apart. Cards from Revised Edition and Unlimited Edition have the following characteristics:

No expansion symbol
No copyright date
Unlimited cards have a double beveled inside border, while Revised cards have a single beveled border
Unlimited card titles are more left justified than Revised
Unlimited card ink colors are darker than Revised

4th Edition & 5th Edition

No expansion symbol
4th Edition has a 1995 copyright
5th Edition has a 1997 copyright

6th, 7th, 8th, 9th Editions

6th Edition has a "VI" expansion symbol & copyright 1993-1999
7th Edition has a "7" expansion symbol & copyright 1993-2001
8th Edition has a "8" expansion symbol & copyright 1993-2003
9th Edition has a "9" expansion symbol & copyright 1993-2005

Other Sets

Chronicles: Chronicles cards are white bordered reprints of cards from Arabian Nights, Antiquites, Legends and the Dark, and have a 1995 copyright date.

Starter: Starter cards have a star for an expansion symbol.