"Reserved" honestly i do not know if it's worth it.
it would be:
-| 0-5 | 6 | 7 | 8-31 | Description |
-|-----|---|---|------|---------------------------|
-| PO | 0 | 0 | nnnn | new, scalar (SVP64Single) |
-| PO | 1 | 0 | 0000 | `RESERVED` |
-| PO | 1 | 0 | !zero | old, scalar (SVP64Single) |
-| PO | 0 | 1 | nnnn | new, vector (SVP64) |
-| PO | 1 | 1 | nnnn | old, vector (SVP64) |
+| 0-5 | 6 | 7 | 8-31 | Description |
+|-----|---|---|-------|---------------------------|
+| PO | 0 | 0 | 0000 | `RESERVED1` |
+| PO | 0 | 0 | !zero | new-suffix, scalar (SVP64Single) |
+| PO | 1 | 0 | 0000 | `RESERVED2` |
+| PO | 1 | 0 | !zero | old-suffix, scalar (SVP64Single) |
+| PO | 0 | 1 | nnnn | new-suffix, vector (SVP64) |
+| PO | 1 | 1 | nnnn | old-suffix, vector (SVP64) |
+
having this `RESERVED` encoding in the middle of the
space does complexify multi-issue decoding somewhat,