Located on the side of the building about 6 feet from the ground, at window level adjacent to the Anzio Mascot plaque.

The history of the FSSF at Anzio for their association website:

Anzio 1944

The Special Force brigade was withdrawn from the mountains {on the Gustav/Winter Line} in January and on February 1 was landed at the beachhead created by Operation Shingle at Anzio, south of Rome, replacing the 1st and 3rd Ranger battalions which had been decimated at Cisterna. Their task was to hold and raid from the right-hand flank of the beachhead marked by the Mussolini Canal/Pontine Marshes. Shortly after the FSSF took over the Mussolini Canal sector, German units pulled back up to a half-mile to avoid their aggressive patrols.

It was at Anzio that the Germans dubbed the 1st Special Service Force the "Devil's Brigade." The diary of a dead German soldier contained a passage that said, "The black devils (Die schwarzen Teufel) are all around us every time we come into the line."[citation needed] The soldier was referring to them as "black" because the brigade's members smeared their faces with black boot polish for their covert operations in the dark of the night. During Anzio, the 1st SSF fought for 99 days without relief. It was also at Anzio that the 1st SSF used their trademark stickers; during night patrols soldiers would carry stickers depicting the unit patch and a slogan 

written in German: "Das dicke Ende kommt noch," said to translate to "The Worst is yet to Come", placing these stickers on German corpses and fortifications. Canadian and American members of the Special Force who lost their lives are buried near the beach in the Commonwealth Anzio War Cemetery and the American Cemetery in Nettuno, just east of Anzio

When the 5th Army breakout offensive began on May 25, 1944, the 1st SSF was sent against Monte Arrestino, and attacked Rocca Massima on May 27. The 1st SSF was given the assignment of capturing seven bridges in the city to prevent their demolition by the withdrawing Wehrmacht. During the night of June 4, members of the 1st SSF entered Rome. They are among the Allied units who claim to be the first to enter Rome. After they secured the bridges, they quickly moved north in pursuit of the retreating Germans.

The text on the plaque is written in Italian.  It reads:

IN MEMORIAM

IL 2 FEBBRAIO 1944, 

IL 1 RAGGRUPPAMENTO OPERAZIONE SPECIALI STATUNITENESE-CANADESE

PRESE POSIZIONE LUNGO IL CANALE MUSSOLINI. A DIFESA DI

UN QUARTO DEL PERIMETRO DELLA TESTA DI PONTE DI ANZIO/NETTUNO.

PER 99 GIORNI QUESTA UNITA RESPINSE INSIDIOSI ATTACHE E 

DIEDE BATAGLIA AL NEMICO CON PATTUGLIAMENTI AGGRESSIVI.

IL 23 MAGGIO, IL I RAGGUPPAMENTO 

FU LA PUNTA DELL’ ATTACCO DIRETTO A DISTRUGGERE LE FORZE NEMICHE

CHE CIRCONDAVONO LA TESTA DI PONTE ED A PORTARE ALLA

LIBERAZIONE DI ROMA.  IL 4 GUIGNO 1944.

LA CAMPAGNA D’ITALIA COSTO’ LA VITA A 374 COMPAGNI D’ARME

CON OLTRE 1200 FERITI. AD ESSI ED AI CITTEDINI CHE EBBERO  A SOFFIRE

NEL CORO DEL BATTALGIA CONDOTTE SUL LORO PATRIO SOULO

DEDICHIAM QUESTA LAPIDE.

ASSOCIAZIONE 1 RAGGUPPAMENTO OPERAZIONE SPECIALI 

MEMORIAL DAY

27 MAGGIO 1991

THE TRANSLATION IN ENGLISH:

IN MEMORIAM

2 FEBRUARY 1944

THE 1^ST SPECIAL SERVICE FORCE SPECIAL AN UNITED STATES-CANADIAN UNIT

TOOK POSITIONS ALONG THE MUSSOLINI CANAL.  A DEFENSE OF

ONE-FOURTH OF THE ANZIO-NETTUNO BRIDGEHEAD PERIMETER.

FOR 99 DAYS THIS UNIT HELD BACK INSIDIOUS ENEMY ATTACKS

AND FOUGHT BACK THE ENEMY WITH AGGRESSIVE PATROLLING.

ON 23 MAY 1944, THE FORCE

LED THE ATTACK OF THE BRIDGEHEAD BREAKOUT 

AND LEAD THE LIBERATION OF ROME ON 4 JUNE 1944.

THE ITALIAN CAMPAIGN COST THE LIVES OF 374 COMRADES IN ARMS

AND ANOTHER 1200 WOUNDED ALONG WITH THE CITIZENS WHO SUFFERED

IN THE HEART OF THE BATTLE FOUGHT ON THEIR HOMELAND

WE DEDICATE THIS PLAQUE.

THE ASSOCIATION OF THE 1^ST SPECIAL SERVICE FORCE

MEMORIAL DAY

27 MAY 1991