Source: Per post by Allan Miller at 18th Battalion Facebook Group.
This man enlisted with the 186th Battalion on November 22, 1915. His reg. no. was 189423. Going overseas, he was transferred to combat duties with the 18th Battalion CEF and arrived on November 20, 1917. He contracted diphtheria on November 28, 1917, and returned to England for treatment. He did not recover sufficiently for further combat service and returned to Canada September 24, 1918.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 