Apologies for my ignorance, but why would 1 company have 2 different market identifier codes? I have found that Clearstar Inc has both LON:CLST and LON:CLSU, with each seemingly identical except for the share price.
Hey - it looks like a technical issue to do with how the original AIM admission was done.
CLSU shares trade inside Crest and the old CLST trade outside of Crest. This kind of explains it - http://www.stockopedia.com/share-prices/clearstar-inc-LON:CLST/news/rns/150713clst9159s.htm/?title=clearstar-shares-to-be-traded-on-crest
