Well count me as the second person. They are the very same thing, I do not know how old you are but this is always what LSD was called. Blotter, windowpane, liquid, sugar cubes, you name it, it was acid. The reason why it was called Acid is right there in the name of the drug: Lysergic
acid diethylamide
If the substantiation of a second person is not sufficient for you then here the very first line of the wikipedia article on LSD: "Lysergic acid diethylamide, abbreviated LSD or LSD-25, also known as lysergide (INN) and
colloquially as acid
"If that is not convincing enough for you, here it is from the DEA:
"What are common street names?
Common.names.for.LSD.include:.
➔»»
Acid, Blotter Acid, dots, Mellow Yellow, and
Window Pane"
http://www.justice.gov/dea/pr/multimedia-library/publications/drug_of_abuse.pdf#page=65