Interactive Brokers order ticket

[PowerM]

Hi, I have a question concerning the order ticket for Interactive Brokers.
I wonder what this field "Display size" is being used for.
I got the ticket by clicking on "buy" in a chart.
Does anybody know this?
Thanks a lot in advance!

[eSignal_AveryH]

This field is generally used to disguise large orders as smaller one. This is also known as an Iceberg/Reserve orders.