1. A computer program product for translation of a virtual address into a translated address of a desired block of main storage in a computer system of a machine architecture, the translation controlling whether a memory store operation to a desired block of main storage will set an indication that the desired block of main storage has been chanced, the computer program product comprising: a non-transitory computer storage medium readable by said computer system, said computer storage medium storing instructions for performing a method comprising: based on a memory store operation to be performed, performing an address translation of a virtual address of the memory store operation, to obtain a translated address of a desired block of main storage of the memory store operation, wherein the address translation is based on a translation table entry of a translation table, the translation table entry comprising an address field and a change override (CO) field, wherein the desired block of main storage has an associated change (C) field for indicating whether said block of main storage has been modified, the C field having any one of a first C value indicating the desired block of main storage has been modified or a second C value indicating the desired block of main storage has not been modified; based on the obtained translated memory address, initiating, by the computer system, the memory store operation to said desired block of main storage at said obtained translated memory address, the store operation storing data to said desired block of main storage; and based on the change override (CO) field of the translation table entry having a first CO value, the initiated memory store operation causing the associated C field to have the first C value; and based on the CO field of the translation table entry having the second CO value, the initiated memory store operation not causing the associated C field to have the first C value.