Use of 'iv_trigger_submit' ??

I have created value help on a context node by writing the below code. What is the use of iv_trigger_submit?? It s behaving the same for both abap_true and abap_false.

CREATE OBJECT rv_valuehelp_descriptor TYPE cl_bsp_wd_valuehelp_f4descr

EXPORTING

iv_help_id = 'ZSEARCH'

iv_help_id_kind = if_bsp_wd_valuehelp_f4descr=>help_id_kind_comp

iv_input_mapping = lt_inmap

iv_output_mapping = lt_outmap

iv_trigger_submit = abap_true.

Thanks,

Ritu