Enable Descriptive Flexfields [DFF] in a Custom Forms

Steps for creating DFF in Custom Form

Go to Application Developer
Flex Fields----------Descriptive Flex Fields
1) Select the application: Appropriate Top
2) DFF Name: You’r Choice
3) Title: You’r Choice
4) Description: You’r Choice
5) Table Name: The name which we are using in the Block (We need to create using

Table :EXECUTE ad_dd.register_table('XXTCC', 'XXTBK_OPM_INGRID_BATCH', 'T',8, 10, 90);

Columns
EXECUTE ad_dd.register_column('XXTCC', 'XXTBK_OPM_INGRID_BATCH','ATTRIBUTE_CATEGORY1',19, 'VARCHAR2', 150, 'N', 'N');
EXECUTE ad_dd.register_column('XXTCC', 'XXTBK_OPM_INGRID_BATCH','ATTRIBUTE1',20, 'VARCHAR2', 50, 'N', 'N');
EXECUTE ad_dd.register_column('XXTCC', 'XXTBK_OPM_INGRID_BATCH','ATTRIBUTE2',21, 'VARCHAR2', 50, 'N', 'N');
EXECUTE ad_dd.register_column('XXTCC', 'XXTBK_OPM_INGRID_BATCH','ATTRIBUTE3',22, 'VARCHAR2', 50, 'N', 'N');

EXECUTE ad_dd.register_column('XXTCC', 'XXTBK_OPM_INGRID_BATCH','ATTRIBUTE4',23, 'VARCHAR2', 50, 'N', 'N');
EXECUTE ad_dd.register_column('XXTCC', 'XXTBK_OPM_INGRID_BATCH','ATTRIBUTE5',24, 'VARCHAR2', 50, 'N', 'N');

And fill all the above details as below.

Click on Columns Select the list of columns to be displayed in DFF

Next
Segments:Query your DFF

Attach the Value set or leave it as blank

incase user will enter manually.

These are all the steps to be followed to create a DFF in Custom Form.
And next go to forms
The below are two mandatory steps to be followed in FMB1) Create Item ITEM_DFF for which property:
TEXT_ITEM_DESC_FLEX
2) And write the below in code in WHEN_NEW_ITEM_INSTANCE for
the item ITEM_DFF
fnd_flex.event ('WHEN-NEW-ITEM-INSTANCE');
3) Finally in WHEN-NEW_FORM_ INSTANCE we have to call the felx filed structure.

fnd_descr_flex.define ( block => Block name in which the DFF
field => Field from which DFF
appl_short_name => 'XXTCC',
desc_flex_name => TCC_PROD_BATCH_DFF'
);