Please refer to the below sample code:
[#Field: IFLT Method]
Delete : Table
Add : Table : MethodTable1 : #IFLTType != "" ;; we add our collection in tally's default field as table
[Collection: MethodTable1] ;; This is developer defined collection
Use : MethodTable
Object : ChequeNoObject
[Object : ChequeNoObject] ;; Our defined object
UserMethodName : "Cheque No" ;; Display name in Table
Method Name : VchChequeNumber ;; Storage name in voucher
CollectionSource : "" ;; current collection
SecondaryObject : "" ;; as storage is at voucher
MethodType : "Number" ;; Storage type on basis of which you would get comparison operators
[#Collection: Daybook Vouchers of Company]
Add: Fetch: VchChequeNumber ;; Fetch the required UDF in this collection