I can't help with "Hout", but in the FSU (Former Soviet Union) "M-100" is the nomenclature for the most common brand of Fuel Oil. It is often bought by refiners in the West as Soviet refineries frequently have poor separation between the cuts, so M-100 often contains a significant portion of gas oils. M-100 could source from any crude in the region, so long as it met the product specification, so you cannot make any assumption about corrosion properties. Let me know if this is what you are after, and I could paste the specification.