OptAttribute

FIX Field 206

Tag	Name	Type	Enumerated	First introduced
206	OptAttribute	char		FIX.4.1

Provided to support versioning of option contracts as a result of corporate actions or events. Use of this field is defined by counterparty agreement or market conventions.

Notes

Please post comments, clarifications, examples here. Click on the edit button on the right and away you go! 

Don't forget to refer to the FPL Discussion Groups to back up anything you write.
You will often find the authoritative statements on matters of FIX specification interpretation there.
Links from FIXwiki pages to relevant discussions on the FPL site are very valuable.

For example if you were writing a clarification on how to specify the "quantity" of an order in FIX, you might add the
following relevant link, http://www.fixprotocol.org/discuss/read/f5014573, to back up your points.