This is the first episode in which it is revealed that Colonel Hall, while he was attending officer's training school, was derisively nicknamed 'Old Melon Head.' The term will reappear several more times during the remainder of the series.
Per the title, a bivouac refers to a military encampment made with tents, improvised shelters or any similar arrangement for scouts, mountain climbers or hikers.
In Mickey Freeman's book about Bilko (Behind the lines with Phil Silvers) his plot line for this episode describes a different ending than the one seen on TV.