Perhaps when there are two distinct fault lines involved they give each a unique "quake" status. Then "fore" and "after" shocks would apply only to precedent or subsequent quakes occurring on the same fault line.
Just a guess however.
That is what they said about the two off of Oregon Coast last week, the local paper had artcles stating that the place is not a usual area and they are not conclusive on what to think.
Our coast has a tsunami emergency alert but the raido could not get any info or confirmation and the County website did not have any info the local paper chewed out the Commisioners for the lack of emergency preparedness and we already have a plan in action. City hall phone lines jammed.
My freind who owns a rv/boat resort has decided my road is going to be the high ground road she uses since it is well kept and paved/trees removed ect.