This May 1942 notice orders sailors to wear only cap ribbons with the letters "HMCS" (His Majesty's Canadian Ship).

In peacetime, cap ribbons (often called cap tallies) carried the name of a sailor's ship. This was prohibited in wartime to avoid identifying which ships were visiting a port, information that could prove useful to an enemy. In an attempt to preserve some sort of identity, sailors took to wearing cap ribbons identifying their ship types, such as destroyers or minesweepers. These were also prohibited since they identified the types of ships visiting a port.

George Metcalf Archival Collection
CWM 19850443-001

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