Rick, APQC has a process classification framework for banking that might suit your initial needs. Here is a link for more information.
I had already looked at that one. I didn't get the feeling that is was very specific to banking, it still feels very manufacturing-like. Also, I was hoping for something more along the lines of value chains ilke Order-2-Cash, Hire-2-Retire, etc.
You can get parts of the finance ontology which interest you.
It has a federated structure. An example of what you can find as informtion is available here. The main participants in the federation are "Financial instruments", "Involved parties" and Accounts. You can find them here. On that page you will find a link to an example of "ISO20022" implementation
This norm, very well documented here, is to my understanding a very good start for processing financial information and transactions. Looking at the website, don't forget to consult the manuals in collumns "msg definition report", model and diagrams. Also message definition files and examples are provided. If this approach looks attractive to you, there are similar websites on other standards.
If you can consider "states" in the business objects, semantic applications allow "dynamic categorisation" in different states according to the properties of a business object. If you think about a "securities account" as being a business object, then the management of that account is handled through the different statusses it gets according to the messages exchanged. That way, using semantic applications you can execute processes described as stages or states in which a business object can transit.
You can find examples of semantic applications here.
Those messages would be best supported and documented by BPMN choreographies. Unfortunately they are not (yet) supported by ARIS tools. So, meanwhile BPMN collaboration diagrams have to be used.
Hope the information is broad enough to help you find your way out.
Thanks Eddy. Those are some great resources.