OGX "market access warrants" appeared on the United Kingdom's Financial Services Authority's Official List (as did MMX, LLX, and MPX warants).What, precisely, a "market access warrant" is... I have no idea.http://www.reuters.com/article/2011/11/18/idUS68903+18-Nov-2011+RNS20111118...about the middle of the page.RNS is the news service for the LSE.
I think these are equivalent to the type of pink sheet ADR we have in US.
PS: EBX companies do not yet meet the requirement for full LSE listing including three years of financials. So they went ADR-equivalent route for now.