+Various valid long-term desireable situations coexist, and while discussing immediate countermeasures, it is useful to keep the long-term outcome that those are most likely to produce.
+
+These are the five possible situations at the time of bullseye (buster + 1):
+
+* `none`: "merged `/usr`" has been reverted
+* `weak`: both directory schemes are allowed, packages only built on classical hosts
+* `middle`: both directory schemes are allowed, packages can be built anywhere
+* `hard`: both directory schemes are allowed, packages only built on "merged `/usr`" hosts
+* `all`: only "merged `/usr`" directory schemes are allowed, packages only built on "merged `/usr`" hosts
+
+It can be summarized by the following table:
+
+```
+| | Host types that are allowed | Are merged-/usr | Official packages are built on | Packages built on … can break on the other |
+| Codename | classical hosts | merged-/usr hosts | symlinks allowed | classical hosts | merged-/usr hosts | classical hosts | merged-/usr hosts |
+|----------|-----------------|-------------------|------------------|—----------------|-------------------|---------------------|----------------------|
+| none | yes | no | no | yes | no | yes | yes |
+| weak | yes | yes | yes | yes | no | no | yes |
+| middle | yes | yes | yes | yes | yes | no | no |
+| hard | yes | yes | yes | no | yes | no | no |
+| all | no | yes | yes | no | yes | yes | no |
+```
+
+## Immediate actions
+
+Given that hosts with different top-level directory schemes already exist; there are various ways forward that would allow for Debian to converge to a desireable situation: