diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index da8be8c..9169419 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,16 +8,32 @@ on:
   pull_request:
 
 jobs:
+  pr-target-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fail if target is not staging (for PRs only)
+        if: github.event_name == 'pull_request'
+        run: |
+          if [[ "${{ github.event.pull_request.base.ref }}" != "main" || "${{ github.event.pull_request.head.ref }}" == "staging" ]]; then
+            echo "Target branch is acceptable."
+          else
+            echo "Only PRs from staging can target main."
+            exit 1
+          fi
+          
   tests:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
       - name: Set up Python 3.11
         uses: actions/setup-python@v2
         with:
           python-version: 3.11
 
-      - name: run pre-commit
+      - name: Run pre-commit
         run: |
           python -m pip install pre-commit
           pre-commit run --all-files
diff --git a/.github/workflows/preview.yml b/.github/workflows/preview.yml
index 6796c1c..c674eb6 100644
--- a/.github/workflows/preview.yml
+++ b/.github/workflows/preview.yml
@@ -2,6 +2,8 @@ name: Deploy PR previews
 
 on:
   pull_request:
+    branches:
+      - main
     types:
       - opened
       - reopened
diff --git a/index.qmd b/index.qmd
index a69de9b..1e2a749 100644
--- a/index.qmd
+++ b/index.qmd
@@ -59,7 +59,7 @@ Notes:
     - GeoParquet and FlatGeobuf can be used for vector data or point cloud data.
 - LAS files are intended for 3D points, not 2D points (since COPC files are compressed LAS files, the same goes for COPC files).
 - [TopoJSON](https://github.com/topojson/topojson) (an extension of GeoJSON that encodes topology) and [newline-delimited GeoJSON](https://stevage.github.io/ndgeojson/) are types of GeoJSON worth mentioning but have yet to be explicitly represented in the diagram.
-- GeoTIFF and GeoParquet are geospatial versions of the non-geospatial file formats TIFF and Parquet, respectively. FlatGeobuf builds upon the non-geospatial [flatbuffers](https://github.com/google/flatbuffers) serialization library (though flatbuffers is not a standalone file format)
+- GeoTIFF and GeoParquet are geospatial versions of the non-geospatial file formats TIFF and Parquet, respectively. FlatGeobuf builds upon the non-geospatial [flatbuffers](https://github.com/google/flatbuffers) serialization library (though flatbuffers is not a standalone file format).
 
 ## Table of Contents