Can be used for SecurityType (167)=OPT to identify a particular security.

Valid values vary by SecurityExchange (207):

For Exchange: MONEP (Paris)

L = Long (a.k.a. 'American')

S = Short (a.k.a. 'European')

For Exchanges: DTB (Frankfurt), HKSE (Hong Kong), and SOFFEX (Zurich)

0-9 = single digit 'version' number assigned by exchange following capital adjustments (0=current, 1=prior, 2=prior to 1, etc).