How minimum move works for infantry?

A4.134. If infantry unit retains at least one MF after deducting for portage cost exceeding its IPC, it may make a Minimum Move of one hex during MPh even if CX. Hex cannot be with terrain of NA (not allowed) movement cost. After entering a hex with a Minimum Move and undergone First Fire if any, all unbroken survivors of such move becomes both pinned and CX.