I recently came across the following rule form the Florida Rules of Professional Conduct:

Unidentifiable Trust Fund Accumulations and Trust Funds Held for Missing Owners. When an attorney’s trust account contains an unidentifiable accumulation of trust funds or property, or trust funds or property held for missing owners, such funds or property shall be so designated. Diligent search and inquiry shall then be made by the attorney to determine the beneficial owner of any unidentifiable accumulation or the address of any missing owner. If the beneficial owner of an unidentified accumulation is determined, the funds shall be properly identified as the lawyer’s trust property. If a missing beneficial owner is located, the trust funds or property shall be paid over or delivered to the beneficial owner if the owner is then entitled to receive the same. Trust funds and property that remain unidentifiable and funds or property that are held for missing owners after being designated as such shall, after diligent search and inquiry fail to identify the beneficial owner or owner’s address, be disposed of as provided in applicable Florida law.