2c39975a_ML_Message_Information___is2Qb__Meaning
[Attribute] retCount [Restrictions] Optional [Meaning] 
If you specify metaData to be returned in a query request message, QuickBooks will return the retCount containing the approximate count of the objects that could be expected to be returned from the query. You should be aware that the count returned in retCount is not guaranteed to be exact: it could be off slightly due to new object creation or deletions.
QBXML Message Information | is2Qb
Meaning