When Germany invaded Poland in 1939, Canada leaped to defend the freedom of Europe and declared war. Its citizens raced to enlist in the armed forces to contribute to the effort.
Many of them were rejected because they had medical problems that prevented them from serving effectively. This was a source of disappointment to many and embarrassment to some as they faced public shaming by ignorant fellow citizens who thought that they should be in uniform.
So the Canadian government created a badge that these men could wear to deter their critics. It was a silver or rhodium plated badge that said in either English or French "Applicant for Enlistment - Canada." It affirmed that the person had tried to enlist, but was rejected through no fault of his own. Veterans Affairs Canada quotes the Order in Council that created it:
Persons who have voluntarily declared their unqualified willingness to serve in and beyond Canada in the Military Forces of Canada, and who are refused enlistment by reason of their not possessing, due to no faults of their own, the necessary qualifications then required for enlistment in the Naval, Army and Air Forces of Canada.
-via reddit | Image: Veterans Affairs Canada