If you have people that are giving money for a retreat or event, these monies are not tax deductible and should not be displayed on the year end giving statement.  To do this you'll need to set up a fund in the chart of accounts that is marked as "not on receipt".  Use the following steps:

1)  Select Donations>Chart of Accounts
2)  Click Add Account
3)  Enter the fund name and mark the box for "not on receipt"
4)  Click OK to save the fund

When you are entering the donations, you can enter this amount for the donor and designate it to the fund you created in step 3 above.