diff --git a/crates/gc-formats/src/gs.rs b/crates/gc-formats/src/gs.rs
index b969100..bc4add9 100644
--- a/crates/gc-formats/src/gs.rs
+++ b/crates/gc-formats/src/gs.rs
@@ -13,6 +13,24 @@
 //!   texel rather than repeating it.
 //!
 //! Nothing here touches wgpu: these are the rules the renderer must feed it.
+//!
+//! # Which of these are actually wired
+//!
+//! Stated explicitly, because a rule that exists in a module is not a rule the
+//! renderer applies -- and the sampler in `gc-engine` sat behind a comment
+//! claiming it clamped while the code did `..default()`, which is `Repeat`. The
+//! failure mode here is a reader assuming a function is in the draw path because
+//! it is in a file called `gs.rs`.
+//!
+//! | rule | wired? | where |
+//! |---|---|---|
+//! | CLAMP wrap | **yes** | `gc-engine`'s `image_of` sets `address_mode_u/v` |
+//! | alpha `0x80` is opaque | **yes** | `texture::scale_alpha` delegates here |
+//! | blend / alpha test | **no** | bevy's `AlphaMode` cannot express both at once |
+//! | mip selection | **no** | only level 0 is decoded, so `mip_level` is always 0 |
+//!
+//! `passes_alpha_test` and `BlendMode` are reference: correct, tested, and not on
+//! the draw path. That is a deliberate state, not an oversight.
 
 /// Alpha is 7-bit, so `0x80` is fully opaque rather than half-transparent.
 ///