How to set the tag <OrdType>?

Imported from previous forum

Hallo!

Is there a way to drop the Value-attribute and specify the Ordertype like the following?

<OrdType>
<MarketOrder>1</MarketOrder>
</OrdType>

Why is it necessary to specify a Sub-Tag (MarketOrder, LimitOrder) when
this informationen is already comprised in the Ordertype value?

Thanks in advance!
Best regards,
Markus Lubenik