diff --git a/CHANGELOG.md b/CHANGELOG.md
index 387a4c07..794eda2f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,9 @@ The release run heads these entries with the version and opens a fresh
   short values is still a csv. One record is a line, not a table.
 - A large text file appears at once: sizing the line numbers laid the page out
   once per line. A megabyte took 38s and now takes under a second.
+- **Deprecated** `HtmlConfig::embed_outline`, `no_drm`,
+  `background_image_format` and `background_image_dpi`. Nothing has read them
+  for a while; they still store and return what is set.
 
 ## v6.7.1 - 2026-08-16
 
diff --git a/apple/include/OdrCoreObjC/ODRHtml.h b/apple/include/OdrCoreObjC/ODRHtml.h
index 8b46496c..816eef9c 100644
--- a/apple/include/OdrCoreObjC/ODRHtml.h
+++ b/apple/include/OdrCoreObjC/ODRHtml.h
@@ -100,7 +100,9 @@ NS_SWIFT_NAME(HtmlConfig)
 @property(nonatomic) uint8_t htmlIndent;
 @property(nonatomic, copy) NSString *htmlIndentString;
 
+/// @deprecated Inert.
 @property(nonatomic, copy) NSString *backgroundImageFormat;
+/// @deprecated Inert.
 @property(nonatomic) double backgroundImageDpi;
 
 /// Render only pages `[begin, end)`, 0-based. `nil` end means to the last page.
@@ -111,7 +113,9 @@ NS_SWIFT_NAME(HtmlConfig)
 @property(nonatomic, copy) NSArray<NSString *> *pdfDualLayerFallbackFonts;
 @property(nonatomic) double pdfDualLayerFallbackFontSizeAdjust;
 
+/// @deprecated Inert.
 @property(nonatomic) BOOL noDrm;
+/// @deprecated Inert.
 @property(nonatomic) BOOL embedOutline;
 
 @property(nonatomic, copy, nullable) NSString *outputPath;
diff --git a/jni/java/app/opendocument/core/HtmlConfig.java b/jni/java/app/opendocument/core/HtmlConfig.java
index 4d9c3a61..fd1cc301 100644
--- a/jni/java/app/opendocument/core/HtmlConfig.java
+++ b/jni/java/app/opendocument/core/HtmlConfig.java
@@ -42,8 +42,11 @@ public final class HtmlConfig {
   public int htmlIndent = 1;
   public String htmlIndentString = "\t";
 
-  public String backgroundImageFormat = "png";
-  public double backgroundImageDpi = 144.0;
+  /** @deprecated Inert. */
+  @Deprecated public String backgroundImageFormat = "png";
+
+  /** @deprecated Inert. */
+  @Deprecated public double backgroundImageDpi = 144.0;
 
   public int pageRangeBegin = 0;
   /** {@code null} renders to the end of the document. */
@@ -55,9 +58,11 @@ public final class HtmlConfig {
   };
   public double pdfDualLayerFallbackFontSizeAdjust = 0.5;
 
-  public boolean noDrm = false;
+  /** @deprecated Inert. */
+  @Deprecated public boolean noDrm = false;
 
-  public boolean embedOutline = false;
+  /** @deprecated Inert. */
+  @Deprecated public boolean embedOutline = false;
 
   /** {@code null} keeps output in the cache directory. */
   public String outputPath;
diff --git a/python/src/bind_html.cpp b/python/src/bind_html.cpp
index 956b1d17..ad0b8fa6 100644
--- a/python/src/bind_html.cpp
+++ b/python/src/bind_html.cpp
@@ -94,9 +94,11 @@ void odr_python::bind_html(py::module_ &m) {
       .def_readwrite("html_indent", &odr::HtmlConfig::html_indent)
       .def_readwrite("html_indent_string", &odr::HtmlConfig::html_indent_string)
       .def_readwrite("background_image_format",
-                     &odr::HtmlConfig::background_image_format)
+                     &odr::HtmlConfig::background_image_format,
+                     "Deprecated and inert.")
       .def_readwrite("background_image_dpi",
-                     &odr::HtmlConfig::background_image_dpi)
+                     &odr::HtmlConfig::background_image_dpi,
+                     "Deprecated and inert.")
       .def_readwrite("page_range_begin", &odr::HtmlConfig::page_range_begin)
       .def_readwrite("page_range_end", &odr::HtmlConfig::page_range_end)
       .def_readwrite("pdf_text_mode", &odr::HtmlConfig::pdf_text_mode)
@@ -104,8 +106,10 @@ void odr_python::bind_html(py::module_ &m) {
                      &odr::HtmlConfig::pdf_dual_layer_fallback_fonts)
       .def_readwrite("pdf_dual_layer_fallback_font_size_adjust",
                      &odr::HtmlConfig::pdf_dual_layer_fallback_font_size_adjust)
-      .def_readwrite("no_drm", &odr::HtmlConfig::no_drm)
-      .def_readwrite("embed_outline", &odr::HtmlConfig::embed_outline)
+      .def_readwrite("no_drm", &odr::HtmlConfig::no_drm,
+                     "Deprecated and inert.")
+      .def_readwrite("embed_outline", &odr::HtmlConfig::embed_outline,
+                     "Deprecated and inert.")
       .def_readwrite("output_path", &odr::HtmlConfig::output_path)
       .def_readwrite("resource_locator", &odr::HtmlConfig::resource_locator);
 
diff --git a/src/odr/html.hpp b/src/odr/html.hpp
index 2f7cfa8e..3a908564 100644
--- a/src/odr/html.hpp
+++ b/src/odr/html.hpp
@@ -155,8 +155,9 @@ struct HtmlConfig {
   std::uint8_t html_indent{1};
   std::string html_indent_string{"\t"};
 
-  // background image
+  /// @deprecated Inert: no view renders a background image to a file.
   std::string background_image_format{"png"};
+  /// @deprecated See @ref background_image_format.
   double background_image_dpi{144.0};
 
   // Paged-document page range (currently honored by the PDF pipeline): render
@@ -177,10 +178,10 @@ struct HtmlConfig {
       "Arial", "Helvetica", "Liberation Sans", "DejaVu Sans", "Nimbus Sans"};
   double pdf_dual_layer_fallback_font_size_adjust{0.5};
 
-  // drm options
+  /// @deprecated Inert: no output carries a restriction to lift.
   bool no_drm{false};
 
-  // outline options
+  /// @deprecated Inert: an outline is never written.
   bool embed_outline{false};
 
   std::optional<std::string> output_path;
diff --git a/wasm/js/index.d.ts b/wasm/js/index.d.ts
index d2e3de29..66b1e569 100644
--- a/wasm/js/index.d.ts
+++ b/wasm/js/index.d.ts
@@ -74,9 +74,13 @@ export interface HtmlConfig {
   editable?: boolean;
   textDocumentMargin?: boolean;
   formatHtml?: boolean;
+  /** @deprecated Inert. */
   embedOutline?: boolean;
+  /** @deprecated Inert. */
   noDrm?: boolean;
+  /** @deprecated Inert. */
   backgroundImageFormat?: string;
+  /** @deprecated Inert. */
   backgroundImageDpi?: number;
   pageRangeBegin?: number;
   pageRangeEnd?: number;