Room E14-140 on the first floor of the Fumihiko Maki-designed Media Lab building, houses a cluster of the student offices of the MIT Program in Art, Culture and Technology. Participants of the program call the space the Venus Lab, but the door is clearly labeled:
MASTERCARD FUTURE OF
TRANSACTIONS LABORATORY
This label is residue of a flopped MediaLab research group that was originally intended for the space:
The “MasterCard Future of Transactions Laboratory” will be a core resource for MIT’s new e-markets special interest group (SIG), composed of manufacturers, distributors and technology companies who will study the future of commerce. The work in the laboratory will include the development of innovative technologies that help consumers, businesses, and retailers conduct transactions easily, efficiently and securely. source
TRANSACTIONS also means:
5. the published records of the proceedings, as papers read, addresses delivered, or discussions, at the meetings of a learned society or the like.
eg, the “Philosophical Transactions of the Royal Society”, the world’s first science journal, published by the word’s first learned society:

[journal available at the MIT library: http://library.mit.edu/item/000298561]
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the “Royal Society of London”. The Society today acts as a scientific advisor to the British government, receiving a parliamentary grant-in-aid. The Society acts as the UK’s Academy of Sciences, and funds research fellowships and scientific start-up companies.
The Royal Society was partially an extension of the informal Invisible College.
The organizing group of the MASTERCARD FUTURE OF TRANSACTIONS LABORATORY was SIG:
The e-markets special interest group (SIG) provides an interdisciplinary approach to understanding electronic marketplaces. The SIG draws on faculty at the Media Lab, Sloan and the MIT community. http://e-markets.media.mit.edu/
SIG means:
1. a short personalized message at the end of an e-mail.
2. abbrev. “Signature” a person’s name written in a distinctive way as a form of identification in authorizing a check or document or concluding a letter. the action of signing a document: the license was sent to the customer for signature. a distinctive pattern, product, or characteristic by which someone or something can be identified: the chef produced the pâté that was his signature | [ as modifier ] : his signature dish. OR Music short for key signature or time signature. OR Printing a letter or figure printed at the foot of one or more pages of each sheet of a book as a guide in binding. a printed sheet after being folded to form a group of pages. OR the part of a medical prescription that gives instructions about the use of the medicine or drug prescribed.
3. special interest group
‘SIG,’ in these three senses – as 1) ADDENDUM 2) ABBREVIATION and 3) ACRONYM are representational marks – short sign conventions.
This is the first in a series of abbreviated records of the proceedings of E14-140 to be published as email signatures:
TRANSACTIONS OF E14-140: SIG-1