Example:

No charitable contribution is allowed under IRC 170 (relating to the income tax).

An organization with a suspended exempt status under IRC Section 501(p) doesn’t file Form 990, Return of Organization Exempt From Income Tax, but is required to file the appropriate federal income tax returns for the taxable periods beginning on the date of the suspension. The organization must continue to file all other appropriate federal tax returns, including employment tax returns, and may also have to file federal unemployment tax returns.

If an organization is included on the Treasury Department's Office of Foreign Assets Control (OFAC) Specially Designated Nationals (SDN) list at https://www.treasury.gov/resource-center/sanctions/Pages/default.aspx, and is "suspended" under IRC 501(p), there are several implications, including:

Contributions to the organization become illegal.

Contributions to the organization lose their deductibility.

The organization's assets are frozen.

The Federal Bureau of Investigation or other federal agency will seize and hold the organization’s records; and

No organization or person may challenge a suspension in any administrative or judicial proceeding relating to the federal tax liability of such organization.