If you want to read Lewis' introduction to his own dictionary it's not easy to find out where this is, same with Gaffiot, same with Labaigue and Georges. (The Oxford Latin Dictionary is not available online. There is said to be a subscription to Oxford Scholarly Editions, where it can be accessed but the link is broken and my emails have not been answered). There at least is a link to the abbreviations in the Gaffiot dictionary here http://www.prima-elementa.fr/Gaffiot/Gaffiot-1720.html But there is no such link at prima-elementa.fr for the Lebaigue dictionary. There are only links that start at A and end at Z here: http://www.prima-elementa.fr/Lebaigue/ You would think that Perseus would have a link to an intro to the Lewis and Short dictionary but I have not been able to find it. Logion has all the great Latin dictionaries available online but I see no link to their introductions
It stands to reason that if you're going to post a lexicon online with all sorts of strange abbreviations that you would explain those abbreviations as well.