Are you saying that there is a Field 4: timeline (Link) that is also in your custom doctype? What is the timeline field and what do you mean by: [quote]
associated with Lead or Customer
[/quote]
?
@Dbone
Timeline field seems to be core functionality of Doctype, you can find it in Setup → Doctype → Open Any Document (or Doctype)
please check the screen shot.
I’m not sure how to change that field since it’s part of the initial setup of the doctype.
You could however leave the timeline field blank and write a custom script to insert information into the “Communication” doctype. You would just send “Lead” or “Customer” to it’s “timeline_doctype” field along with the other information needed. Just export some data from the “Communcation” doctype to see what you need to send and in what format.