密而不宣

密 = 宀 + 必 + 山 : Marilyn Monroe (mi) is secretly (密) making out with her secretary (密) Khubilai Khan (必). Because it has to be a secret (密), they meet in the space station's bathroom (Ø4) and hide under a huge graduation cap (宀). Just to be sure Khubilai Khan has two forks (山) in his hands to attack anyone who might enter and see them.

而 = 𦉫 + 丆 : A comb. Albert Einstein is getting ready to go out just inside the entrance of the space station. He put up some loud music on the stereo and tries to comb his hair with his comb and the help of a wind wheel.

不 = 丆 + 卜 : Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.

宣 = 亘 + 宀 : Mnemonic symbol: a big billboard.

There's a big billboard on top of the anthill announcing its new contrail school. Xu Xian just graduated and wearing his graduation cap, he swoops into the air, leaving a contrail outlining a graduation cap. He is so happy he even writes something on the billboard to let everyone know: "I made it!!!"

宣 = 亘 + 宀 : Mnemonic symbol: a big billboard.

There's a big billboard on top of the anthill announcing its new contrail school. Xu Xian just graduated and wearing his graduation cap, he swoops into the air, leaving a contrail outlining a graduation cap. He is so happy he even writes something on the billboard to let everyone know: "I made it!!!"