diff --git a/.github/workflows/data-deploy.yml b/.github/workflows/data-deploy.yml
index dcb3c55..afc6c42 100644
--- a/.github/workflows/data-deploy.yml
+++ b/.github/workflows/data-deploy.yml
@@ -14,6 +14,10 @@ name: Deploy
 #     deploy:
 #       uses: relaton/support/.github/workflows/data-deploy.yml@main
 #
+# Optionally, a caller passes the per-flavor branding its `_config.yml` used to
+# carry — `title`, `favicon` and `description` (see relaton/relaton#96). Left
+# unset, the page carries no favicon and no description, exactly as before.
+#
 # Two source modes (input `source`):
 #   * gem (default) — install the released relaton-cli gem. Ruby only; the gem
 #     ships the precompiled frontend bundle.
@@ -33,6 +37,19 @@ on:
         description: "Index page title (default: '<FLAVOR> Index' from the repo name)"
         required: false
         type: string
+      # Both build steps pass these through unconditionally: relaton-cli treats a
+      # blank value as absent, so the empty default keeps the output identical
+      # for callers that set neither.
+      favicon:
+        description: "Index page favicon URL or output-relative path (default: none)"
+        required: false
+        default: ""
+        type: string
+      description:
+        description: "Index page description (<meta name=\"description\"> and header subtitle)"
+        required: false
+        default: ""
+        type: string
       data-dir:
         description: "Folder of Relaton YAML documents"
         required: false
@@ -129,21 +146,36 @@ jobs:
 
       - name: Build index (gem source)
         if: inputs.source == 'gem'
+        # The branding values are free-form prose, and `${{ }}` is substituted as
+        # raw text before bash parses the line — an inlined description reading
+        # `IEC "TC 1" registry` would word-split into stray argv entries. Passing
+        # them by env hands the runner's verbatim value to the shell.
+        env:
+          FAVICON: ${{ inputs.favicon }}
+          DESCRIPTION: ${{ inputs.description }}
         run: |
           relaton index "${{ inputs.data-dir }}" \
             --output _site \
             --mode "${{ inputs.mode }}" \
             --title "${{ steps.meta.outputs.title }}" \
+            --favicon "$FAVICON" \
+            --description "$DESCRIPTION" \
             --base-url "https://raw.githubusercontent.com/${GITHUB_REPOSITORY}/${GITHUB_REF_NAME}"
 
       - name: Build index (git source)
         if: inputs.source == 'git'
         # BUNDLE_GEMFILE is exported to GITHUB_ENV in the build step above.
+        # FAVICON/DESCRIPTION travel by env for the same reason as the gem step.
+        env:
+          FAVICON: ${{ inputs.favicon }}
+          DESCRIPTION: ${{ inputs.description }}
         run: |
           bundle exec relaton index "${{ github.workspace }}/${{ inputs.data-dir }}" \
             --output "${{ github.workspace }}/_site" \
             --mode "${{ inputs.mode }}" \
             --title "${{ steps.meta.outputs.title }}" \
+            --favicon "$FAVICON" \
+            --description "$DESCRIPTION" \
             --base-url "https://raw.githubusercontent.com/${GITHUB_REPOSITORY}/${GITHUB_REF_NAME}"
 
       - uses: actions/configure-pages@v4
diff --git a/spec/data_deploy_workflow_spec.rb b/spec/data_deploy_workflow_spec.rb
index 82b40bf..2063515 100644
--- a/spec/data_deploy_workflow_spec.rb
+++ b/spec/data_deploy_workflow_spec.rb
@@ -1,19 +1,64 @@
-# Guards the reusable Pages workflow so it resolves gems against Gemfile.deploy
-# (the jekyll + pubid bundle) rather than the data repo's own crawler Gemfile.
+# Guards the reusable Pages workflow's caller contract: it builds the index with
+# `relaton index` (support#58, which replaced the Jekyll build) and forwards the
+# optional per-flavor branding a data repo used to carry in its `_config.yml` —
+# title, favicon and description (relaton#96 added the latter two CLI flags).
+#
+# The two "Build index" steps (gem source / git source) are the fragile part:
+# they are near-duplicate command lines, so a flag added to one and forgotten in
+# the other silently drops branding for every repo on the other source mode.
 RSpec.describe ".github/workflows/data-deploy.yml" do
   repo_root = File.expand_path("..", __dir__)
   workflow = YAML.safe_load_file(File.join(repo_root, ".github/workflows/data-deploy.yml"))
+  # Psych reads the unquoted `on:` key as YAML 1.1 boolean true.
+  inputs = workflow.fetch(true).fetch("workflow_call").fetch("inputs")
   build_job = workflow.fetch("jobs").fetch("build_index_page")
+  index_steps = build_job.fetch("steps").select { |s| s["run"]&.match?(/\brelaton index\b/) }
 
-  it "points BUNDLE_GEMFILE at Gemfile.deploy for the build job" do
-    # setup-ruby's bundler-cache install AND `bundle exec jekyll build` both
-    # honor this env, so the whole job uses the layered deploy bundle.
-    bundle_gemfile = build_job.fetch("env").fetch("BUNDLE_GEMFILE")
-    expect(bundle_gemfile).to end_with("Gemfile.deploy")
+  it "keeps every input optional, so existing callers need no changes" do
+    expect(inputs.values).to all(include("required" => false))
   end
 
-  it "still builds with `bundle exec jekyll build`" do
-    run_steps = build_job.fetch("steps").filter_map { |s| s["run"] }
-    expect(run_steps).to include(a_string_matching(/bundle exec jekyll build/))
+  %w[favicon description].each do |input|
+    describe "the #{input} input" do
+      it "is declared, so callers can pass it" do
+        # A reusable workflow rejects an undeclared input at parse time
+        # ("Invalid input, 'favicon' is not defined in the referenced
+        # workflow"), so a caller cannot work around a missing declaration.
+        expect(inputs).to have_key(input)
+      end
+
+      it "is an optional string defaulting to the empty string" do
+        # The empty default is load-bearing: it lets both build steps pass the
+        # flag unconditionally. relaton's generator runs `presence(...)` on both
+        # values, so `--favicon ""` is indistinguishable from not passing it.
+        expect(inputs.fetch(input))
+          .to include("required" => false, "default" => "", "type" => "string")
+      end
+    end
+  end
+
+  it "builds the index in both source modes" do
+    expect(index_steps.map { |s| s["if"] })
+      .to contain_exactly("inputs.source == 'gem'", "inputs.source == 'git'")
+  end
+
+  %w[favicon description].each do |input|
+    it "hands #{input} to the shell through the environment, not `${{ }}`" do
+      # GitHub substitutes `${{ }}` as raw text before bash parses the line, so
+      # an inlined value is shell source: a description reading
+      # `IEC "TC 1" registry` would word-split into stray argv entries, and one
+      # containing $(...) would execute. Via env the runner passes it verbatim.
+      index_steps.each do |step|
+        expect(step.fetch("env")).to include(input.upcase => "${{ inputs.#{input} }}")
+        expect(step.fetch("run")).not_to include("inputs.#{input}")
+      end
+    end
+  end
+
+  %w[--title --favicon --description --base-url].each do |flag|
+    it "passes #{flag} in every build step" do
+      # Both invocations must stay in sync — see the note at the top.
+      expect(index_steps.map { |s| s.fetch("run") }).to all(include("#{flag} "))
+    end
   end
 end