collection note sub type

Summary:

How to add Notes Sub-type in the Advanced collection notes?

Content (please ensure you mask any confidential information):

Hello Team, 

In advance collection module, for customer notes we have a Type (General, Reference, Collections, Special etc.). But, there is no Sub-type available. Is this feasible to add Notes Subtype? What is the lookup/mapping to add the Note Sub-Type? 

Please advise. Having this notes type(category) and notes subtype(subcategory) is very important for collection business process for this customer.

Version (include the version you are using, if applicable):

24A

Code Snippet (add any code snippets that support your topic, if applicable):