diff --git a/README.md b/README.md
index 0bc32ac..79236af 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,9 @@ new Overworld terrain uses grass slabs to soften suitable one block steps.
 This branch is for Minecraft 1.10.2. Version `1.1.0.110021` requires Forge
 12.18.3.2511 or a compatible Forge 12.18.3 build and Java 8.
 
+The mod works on its own. Sky's Building Pieces and Sky's Terrain Smoother are
+optional; neither is needed to update an existing Grass Slabs world.
+
 ## Installation
 
 Place the mod jar in the `mods` folder. It must be installed on both the client
diff --git a/docs/RELEASE-1.1.0.110021.md b/docs/RELEASE-1.1.0.110021.md
index 79c9800..de11648 100644
--- a/docs/RELEASE-1.1.0.110021.md
+++ b/docs/RELEASE-1.1.0.110021.md
@@ -8,4 +8,9 @@ The mod still works on its own. Existing blocks, recipes, configuration defaults
 and saved migration progress are retained. This release also includes improved
 recovery of legacy slabs in mixed worlds. Back up existing worlds before updating.
 
+Two matching dirt or grass slabs can now be crafted back into a full block.
+When BuildingBricks is absent, three hidden recovery blocks keep historical
+slab IDs separate while the world loads. They do not appear in creative mode,
+but modpacks close to Minecraft 1.10's block-ID limit should allow room for them.
+
 Requires Minecraft 1.10.2, Forge 12.18.3.2511 and Java 8.