The seller of a residence will use the costs of selling to reduce the gain on sale that may either be subject to income tax or excluded when the residence was owned and occupied for at least two of the five years prior to the sale.
Selling costs do not include items that are deductions for federal taxes such as property taxes and mortgage interest (including points).
Both buyer and seller can currently deduct (as part of itemized deductions) property tax and mortgage interest that is paid in closing. Note that reserves are not payments that can be deducted but will later be deductible when actually used.
Depending on the timing of the property tax paid by the seller the item listed on the closing statement may either increase or decrease the amount to be deducted by the seller of the residence. For example, if my locality has me pay in advance (in January for the coming entire year) and I sell on June 30 the buyer will have to pay me for the June-December portion. So, I would have to use the closing statement amount to reduce that January payment for my property tax deduction to report only the amount paid that was not reimbursed to me.
In summary, reserves will not be deducted either as itemized deductions or as costs of selling computing gain, property tax and mortgage interest will be part of itemized deductions in the year of the sale and the remaining items are all part of the costs of selling the residence.
Please ask if you need more discussion or clarification.