E1BPFVDEXP_VDBEPI is a standard SAP Structure which is used to define the field attributes of IDoc segment E1BPFVDEXP_VDBEPI. The segment is used within the below IDoc to send Export Loan: Posted Line Items for Document Header information via the IDoc send process
Below is the standard documentation available and a few details of the fields which make up this IDoc segment structure. To view further details checkout the IDoc links above or use relevant transactions such as WE30(IDoc development), WE31 (segment development)...Also check here for more IDoc related development help, or you can obviously also use standard dictionary object dev tcodes such as SE11, SE80 etc...