Question:

Can the document in the Based on section of a document be deleted in Vault?

Answer:

A document cannot be removed from the Based on section in a document since the Make a Copy feature is used to create this document.

To prevent a document from appearing in the Based on section, the document needs to be created through an upload rather than created from the Make a Copy feature on an existing document. 

Related Documentation:

Vault Documentation:  Vault Help