diff --git a/docs/requirements.md b/docs/requirements.md
index b8d9b59..f8e1bfd 100644
--- a/docs/requirements.md
+++ b/docs/requirements.md
@@ -1330,13 +1330,25 @@ These are targets to design against and measure, on the reference desktop
 | **NFR-P14** | Focus peaking overlay ready | < 100 ms after preview | < 150 ms |
 | **NFR-P15** | Drawn mask stroke → visible (ARCH §6.11) | < 16 ms, no cursor lag | < 16 ms |
 | **NFR-P10** | Touch gesture → visual response | < 16 ms | < 16 ms |
-| **NFR-P11** | Layout class transition (window resize) | No dropped frames, no state loss | n/a |
+| **NFR-P11** | Layout class transition (window resize) | No dropped frames. No loss of *photographic* state: the open image and version, the selection, scroll position, the in-progress edit and its undo history, and the current mode. Panel disclosure is explicitly exempt — see below | n/a |
 | **NFR-P12** | Warm-start shader pipeline setup (cached) | < 100 ms | < 100 ms |
 
 Every target above requires a stated measurement method, workload, and pass threshold before it is
 testable. NFR-P8 in particular must state whether it measures RSS inclusive or exclusive of GPU
 allocations, and whether it holds after SQLite's page cache warms on a 50k catalog.
 
+**On what NFR-P11 means by state.** It said "no state loss", which the implementation contradicts on
+purpose, so the requirement has been made specific rather than left to be read as forbidding
+something it should not. `apply_layout_class` discards the user's panel open/closed choices when the
+class changes, and the argument for that is sound: a choice made in landscape answers a different
+question from the one portrait asks, and carrying it across is how a photographer ends up with a
+232 px sidebar on a screen with no room for it and no memory of having asked for it. Panel
+disclosure is a *default*, re-derived per class, with the user's disagreement remembered only within
+the class where it was expressed.
+
+Everything the photographer produced or navigated to is a different matter, and none of it may be
+touched by a resize. That is the list in the criterion, and it is the testable half.
+
 **Performance regressions fail the build.** §9's benchmark suite runs per-commit; a regression
 beyond a stated tolerance is a build failure, not a notification. Performance work rots otherwise.