I'm not sure that I understood that totally either. Here are the available moves

Number of
Positions A/C Seat Domicile
+14 MD-11 F/O SDF
+18 74Y CPT ANC
+42 74Y F/O ANC
-11 757 F/O SDF
-15 747 CPT SDF
-17 747 F/O SDF
-30 747 S/O SDF
-3 DC-8 CPT SDF
-12 DC-8 F/O SDF

And yet it seems that I saw a very senior 757 domestic captain, seniority 99 I think, moving over to 757Z captain. How does that happen? Like you said, we'll know tomorrow.

Oh, attn new guys: It usually takes the company two or three shots to get these things right <G>