Activity is a set of flags that that controls whether FileMan fires a cross-reference during an installation and/or a re-cross-referencing operation. The possible flags are:
Activity can contain either "I", "R" or both flags together.
FileMan automatically fires cross-references during an edit, regardless of Activity, though you can control whether a cross-reference is fired by entering Set and Kill Conditions.
Also, if you explicitly select a cross-reference in an EN^DIK, EN1^DIK, or ENALL^DIK call, or in the UTILITY FUNCTIONS/RE-INDEX FILE option on the VA FileMan menu, that cross-reference will be fired whether or not its Activity contains an "R".