GMO=genetically engineered organism=GEO
On page 18 of this year's Fedco catalog
(http://www.fedcoseeds.com/forms/sds34_cat.pdf - broken link), in the paragraph titled "Supplier Code," it reads, "We do not offer genetically engineered varieties, although we purchase from corporations engaged in genetic engineering" (Fedco Seeds; 2012 catalog; page 18). In other places on their website you will find the disclaimer that "we do not knowingly sell GMO seeds."
I don't have a beef with Fedco; I buy most of my seeds from them. But I am struck by the language they feel is necessary; I also wonder why it's necessary. Seems like such statements wouldn't be necessary unless there was a doubt/ possibility that GEO seeds were being packaged & sold unlabeled as such.