Use of this flag causes the field to be set to the disabled state. This is mainly useful in GUI mode with opcode 2 (display) to display a field value but indicate to the user (by the fact that it is in dim gray) that it is not presently applicable (and cannot be edited). Since you cannot edit a disabled field, attempting to use this flag with opcode 0 or 1 will cause it to act just like opcode 2, except that any incoming positive exitcode value is preserved (instead of being reset to 0 as would normally be the case with a display operation). This should help your existing field navigation logic to jump over disabled when moving backwards through them.
Note that a normal field display operation (i.e. opcode 2 and cmdflg not containing INFCF_DISABLE) will cause a previously disabled field to be re-enabled. Thus it might be necessary for your program to maintain a separate copy of the cmdflg parameter for every field that might be disabled, in order to preserve its state.
History
2006 February, A-Shell 4.9.951: Function added to A-Shell