Recurring Journals are for transactions that repeat every accounting period. Example: Rent expenses that recur every month.
Mass Allocation Journals are for single journal entry formula that allocates revenues and expenses across a group of cost centers, departments, divisions or cost centers. Example: Redistribute monthly rent expense to departments based on the amount of space each dept occupies.
Rent expense for each dept = Total rent expense x area used by dept/ total area.
TYPE OF ENTRY               RECURRING JOURNALS      MASS ALLOCATION JOURNALS
Formulas per line            one formula per line          one formula for many lines
Formula                               Any formula                   A*B/C