Field help (GADDEBCDT) 

If the answer to this field is No, all the entries generated from this parameter line are grouped together only if they are have all the characteristics listed below in common:
site, general account, business partner account, analytical distribution, nature, tax code, sign
Thus, two entries that have opposite signs but the other characteristics in common are not accumulated.
If the answer is Yes, entries with opposite signs and common characteristics are offset (if the resulting amount is null, the entry is not generated).
Entries done with postings on analytical dimensions without distribution will be grouped together if the other characteristics are identical (a distribution in amount, associated with the general entry line, will then be created)

When several lines generated by a repetitive or linked table line type have the same characteristics (general ledger account, site, BP account, nature, tax code and analytical distribution in the case of of postings done with distribution keys), they are grouped into a single line. If the postings differ by the analytical dimensions, a distribution of the analytical posting amount is created by grouping on a single line at the level of the general accounting. This tick box is used to specify whether the posting sign must also be taken into account during the generation. If the box is ticked, the postings with similar characteristics and different signs are grouped (the total amount being the algebraic sum of the amounts). If not, there will be a posting line for the debit and another for the credit posting.