Most staff and non-faculty academics have 12-month appointments, however most University (non-hospital) faculty members have 9-month (a.k.a. 3Q) appointments. A 9/12 appointment means that an employee earns their salary over nine months or three quarters, but the distribution of the salary is equalized over 12 months. Mathematically, the monthly distribution of a 9/12 appointee's salary is really 75% of their actual earned monthly salary.
For example: a 9/12 appointee with a $120,000 annual salary would earn a monthly salary of $13,333.33 October-June, but would receive a $10,0000 paycheck each month October-September (assuming no salary increase).
In rare cases non-faculty academic employees may also have 9/12 appointments.
Subaccounts 1099 and 1199 are used for the accrual and distributions.
For example: for a faculty appointee with a $120,000 annual salary, you will see on the ledger a $13,333.33 debit in sub-1000 and a $3,333.33 credit in sub-1099 from Oct-June. From July-Sept you will see $10,000 debits in sub-1099.