Definition of Parody
The first scene of the book, and the first chapter generally, parodies a familiar concept in English romantic novels: the character laid up with illness, stuck in a certain place with nowhere to go. Yossarian is stuck in the infirmary with his fake "liver disease," but he's staying of his own volition. (He is lying about his disease in order to stay away from continuing bombing raids, but at this point in the narrative, the reader does not know that yet.)
Milo's black market dealings are bringing him great success in Chapter 24, which Heller describes using a famous allusion:
Unlock with LitCharts A+April had been the best month of all for Milo. Lilacs bloomed in April and fruit ripened on the vine. Heartbeats quickened and old appetites were renewed. In April a lovelier iris gleamed upon the burnished dove. April was spring, and in the spring Milo Minderbinder's fancy had lightly turned to thoughts of tangerines.
Milo's two-timing business dealings, described in Chapter 35, are the subject of another one of Heller's contradictory, ironical constructions:
Unlock with LitCharts A+Milo had been earning many distinctions for himself. He had flown fearlessly into danger and criticism by selling petroleum and ball bearings to Germany at good prices in order to make a good profit and help maintain a balance of power between the contending forces. [...] With a devotion to purpose above and beyond the line of duty, he then raised the price of food in his mess halls so high that all officers and enlisted men had to turn over all their pay to him in order to eat.