Zero value lines in Accounts receivable

I am facing the following case:

We sell products to our clients vat rate 6% or 21% and depending on the customer we invoice them the crates (no vat).

After sales update in AR there are as many lines as there are different vat rates this is OK.

For some of the clients the crates are sold at zero price.  But we keep track of the in- and out movement and they need to be mentioned on the invoice (line is in a status 580 620). 

The issue is that the sales update is creating a zero line in the F03B11 and I was wondering if it was possible to avoid this. In accounting we can avoid this by setting skip zero amounts but I don't know if something like this is possible in accounts receivable.