1975年 - 《一个奇特的装置... Truc... Troc... 您以实物支付！》

In 1975, a press article (unreferenced newspaper) presented the Truc-Troc run for two and a half months by the Château Malou artwork lending gallery: an art "exchange" from which any financial transaction was excluded. "All you need is imagination... lots of imagination... and that should be enough to become the owner of these works." Each visitor proposed an exchange to the artist, who accepted or not.

The article illustrates the principle with humour: "Are you a butcher? Offer, in exchange for a canvas, to supply its author with meat for a year. Do you own marvellous old lace from a great-great-aunt? Offer it in exchange for a work." And it quotes a visitor at the opening: "If I understood correctly, you pay in kind!"

The text publishes the complete eight-article rules of the "exchange market": no financial transaction in any form, an unlimited number of proposals, a definitive exchange upon mutual agreement, each proposal discussed with the artist or their representative, no complaint accepted after the exchange, no official price rating taken into account, works exchanged as they stand with transport at the buyer's expense, and a form to fill in and drop into the ballot box - "the Gallery does the rest".

来源：Coupure de presse, 1975 - journal non référencé