diff --git a/aldc b/aldc
index 3921be0..67f6533 100755
--- a/aldc
+++ b/aldc
@@ -1,8 +1,27 @@
 #! /bin/bash
 # aldc: Add LaTeX DevContainer
 
-REPOSITORY_NAME='latex-environment'
-REPOSITORY_OWNER='smkwlab'
+# Source of the LaTeX devcontainer. Defaults to smkwlab/latex-environment;
+# other orgs can point aldc at their own fork via these env vars.
+REPOSITORY_NAME="${ALDC_REPOSITORY_NAME:-latex-environment}"
+REPOSITORY_OWNER="${ALDC_REPOSITORY_OWNER:-smkwlab}"
+# REPOSITORY_OWNER goes into the download URL; REPOSITORY_NAME is additionally
+# used as the extracted directory in `cd` / `rm -rf` below. Validate both:
+# the GitHub login / repository character set, no leading dash (a leading `-`
+# would be parsed as an option by cd/rm even when quoted), and — for the name —
+# no dot-only / `..` traversal value.
+case "$REPOSITORY_OWNER" in
+    ''|-*|*[!A-Za-z0-9-]*)
+        echo "Error: invalid ALDC_REPOSITORY_OWNER: ${REPOSITORY_OWNER}" >&2
+        exit 1
+        ;;
+esac
+case "$REPOSITORY_NAME" in
+    ''|.|..|-*|*[!A-Za-z0-9._-]*)
+        echo "Error: invalid ALDC_REPOSITORY_NAME: ${REPOSITORY_NAME}" >&2
+        exit 1
+        ;;
+esac
 REPOSITORY_URL="https://github.com/${REPOSITORY_OWNER}/${REPOSITORY_NAME}"
 BRANCH='release'
 ZIP_NAME="${REPOSITORY_NAME}-${BRANCH}.zip"
@@ -41,7 +60,9 @@ while [ $# -gt 0 ]; do
             echo "  --help, -h      Show this help message"
             echo ""
             echo "Environment Variables:"
-            echo "  ALDC_QUIET=1    Enable quiet mode"
+            echo "  ALDC_QUIET=1             Enable quiet mode"
+            echo "  ALDC_REPOSITORY_OWNER    Source org/user (default: smkwlab)"
+            echo "  ALDC_REPOSITORY_NAME     Source repo (default: latex-environment)"
             exit 0
             ;;
         *)
diff --git a/docs/CLAUDE-DEVELOPMENT.md b/docs/CLAUDE-DEVELOPMENT.md
index 74ebaff..4be2614 100644
--- a/docs/CLAUDE-DEVELOPMENT.md
+++ b/docs/CLAUDE-DEVELOPMENT.md
@@ -10,10 +10,24 @@ This document covers the development workflow, architecture, and technical detai
 - **Git Integration**: Automatic repository initialization and commit handling
 
 ### Environment Source
-- **Source Repository**: smkwlab/latex-environment
+- **Source Repository**: smkwlab/latex-environment (default)
 - **Branch**: release (stable releases)
 - **Installation Method**: Downloads ZIP, extracts, and integrates files
 
+The source is overridable for other-org deployments (defaults preserve
+smkwlab behavior):
+
+| Variable | Default | Purpose |
+|----------|---------|---------|
+| `ALDC_REPOSITORY_OWNER` | `smkwlab` | Org/user hosting the latex-environment fork. |
+| `ALDC_REPOSITORY_NAME` | `latex-environment` | Repository name to download. |
+
+`ALDC_REPOSITORY_OWNER` is used only in the download URL; `ALDC_REPOSITORY_NAME`
+is additionally used as the extracted directory in `cd` / `rm -rf`. Both are
+validated (GitHub character set, no leading dash, and — for the name — no `.`
+or `..` traversal) before use. The release branch name is fixed to `release`
+by convention.
+
 ## Installation Process
 
 ### Process Flow
@@ -65,7 +79,7 @@ texlive-ja-textlint (Docker base image)
 ## Configuration Details
 
 ### Default Settings
-- **Repository**: smkwlab/latex-environment
+- **Repository**: smkwlab/latex-environment (override with `ALDC_REPOSITORY_OWNER` / `ALDC_REPOSITORY_NAME`)
 - **Branch**: release (for stability)
 - **Installation Location**: Current working directory
 - **Backup Strategy**: Conflicts renamed with `-aldc` suffix
@@ -99,7 +113,9 @@ texlive-ja-textlint (Docker base image)
 
 ## Security Considerations
 
-- Downloads from official smkwlab repository only
+- Downloads from smkwlab/latex-environment by default; the source is
+  overridable via `ALDC_REPOSITORY_OWNER`/`ALDC_REPOSITORY_NAME`, which are
+  character-validated (no path separators, leading dash, or `.`/`..`)
 - Uses HTTPS for all network communications
 - No external dependencies beyond standard unix tools
 - Repository verification through GitHub's infrastructure