Equities Symbology in fix protocol

Symbology is the process of identifying the symbol for which the  equity order has been sent , symbol could be stock , futures ,options , convertibles , bonds etc.
 

Fix protocol defines many ways to identify the correct symbol which has to be traded. Commonly used tag is Symbol(tag 55) and combination of SecurityID and SecurityID Source.

Different brokers implement in a different way , also fix protocol defines many SecurityID source e.g. RIC (Reuters Information Code) , SEDOL, CUSIP, ISIN , Exchange symbol etc.
 

Same company can be listed in different exchanges and they have different RIC codes for that e.g. Sony has RIC code  6758.T for Tokyo stock exchange and 6758.OS for Osaka Stock Exchange.
RIC is the most widely used SecurityID source , though Japanese market use there own numeric code called “QUIK Code”  e.g. for Sony RIC code is 6758.T and QUIK code is “6758”

RIC code generally use Reuters market symbol as suffix e.g.   “.T” represent Tokyo Stock Exchange while “.OS” represent Osaka Stock Exchange.Exchange symbol is also popular e.g. for Yahoo , exchange symbol is generally “YHOO”

Also Orders for instruments with suffixes (different classes of stock, preferred stock, etc.) can be sent in one of two ways:
• Symbol and Suffix notation (i.e. 55=VIA 65=B, 55=AA 65=PR and 55=IBM 65=PRA)
• Comstock notation (i.e. “VIA.B” “AA-“ and “IBM-A”)

The FIX field for symbol suffixes is SymbolSfx (65). On all execution reports, symbols will be reported in
Symbol and Suffix notation.