SD Document Category is category for sales-related document like Sales Document, Delivery Document, Billing Document, etc.
SD Document Category is predefined hard-coded field, so transaction to define or configure SD Document Category nonexist.
Field ID: VBTYP.
Table: VBAK (Sales Document Header), LIKP (Outbound Delivery Document Header), VBRK (Billing Document Header), etc.
Table with its list: DD07V > Domain: VBTYP.