diff --git a/DESCRIPTION b/DESCRIPTION
index 13d91c5e73..f1ec22c1c7 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -24,4 +24,5 @@ Depends:
     shiny,
     tidyverse,
     webshot2,
-    yaml
+    yaml,
+    yaml12
diff --git a/docs/download/_download-older.yml b/docs/download/_download-older.yml
index 946fd0e2fb..aaf32d9509 100644
--- a/docs/download/_download-older.yml
+++ b/docs/download/_download-older.yml
@@ -39,11 +39,6 @@
   date: 2025-08-29
   path: https://github.com/quarto-dev/quarto-cli/releases/tag/v1.7.34
   changelog: "[Release Notes](changelog/1.7/)"
-- id: version18
-  title: 1.8.27
-  date: 2026-01-16
-  path: https://github.com/quarto-dev/quarto-cli/releases/tag/v1.8.27
-  changelog: "[Release Notes](changelog/1.8/)"
 - id: version18
   title: 1.8.27
   date: 2026-01-16
diff --git a/renv.lock b/renv.lock
index 7448bbf517..157a5f9b97 100644
--- a/renv.lock
+++ b/renv.lock
@@ -6231,6 +6231,40 @@
       "Maintainer": "Hadley Wickham <hadley@posit.co>",
       "Repository": "P3M"
     },
+    "yaml12": {
+      "Package": "yaml12",
+      "Version": "0.1.0",
+      "Source": "Repository",
+      "Title": "Fast 'YAML' 1.2 Parser and Formatter",
+      "Authors@R": "c( person(\"Tomasz\", \"Kalinowski\", , \"tomasz@posit.co\", role = c(\"aut\", \"cre\")), person(\"Posit Software, PBC\", role = c(\"cph\", \"fnd\"), comment = c(ROR = \"03wc8by49\")), person(\"Authors of the dependency Rust crates\", role = \"cph\", comment = \"See inst/AUTHORS and LICENSE.note for vendored Rust dependency authors and licenses.\") )",
+      "Description": "A fast, correct, safe, and ergonomic 'YAML' 1.2 parser and generator written in 'Rust'. Convert between 'YAML' and simple 'R' objects with full support for multi-document streams, tags, anchors, and aliases. Offers opt-in handlers for custom tag behavior and round-trips common 'R' data structures. Implements the 'YAML' 1.2.2 specification from the 'YAML' Language Development Team (2021) <https://yaml.org/spec/1.2.2/>. Proudly supported by Posit.",
+      "License": "MIT + file LICENSE",
+      "URL": "https://posit-dev.github.io/r-yaml12/, https://github.com/posit-dev/r-yaml12",
+      "BugReports": "https://github.com/posit-dev/r-yaml12/issues",
+      "Depends": [
+        "R (>= 4.2)"
+      ],
+      "Suggests": [
+        "jsonlite",
+        "knitr",
+        "rmarkdown",
+        "testthat (>= 3.0.0)",
+        "waldo",
+        "withr"
+      ],
+      "VignetteBuilder": "knitr",
+      "Config/Needs/website": "tidyverse/tidytemplate",
+      "Config/rextendr/version": "0.4.2.9000",
+      "Config/testthat/edition": "3",
+      "Config/testthat/parallel": "false",
+      "Encoding": "UTF-8",
+      "RoxygenNote": "7.3.3",
+      "SystemRequirements": "Cargo (Rust's package manager), rustc >= 1.70.0, xz",
+      "NeedsCompilation": "yes",
+      "Author": "Tomasz Kalinowski [aut, cre], Posit Software, PBC [cph, fnd] (ROR: 03wc8by49), Authors of the dependency Rust crates [cph] (See inst/AUTHORS and LICENSE.note for vendored Rust dependency authors and licenses.)",
+      "Maintainer": "Tomasz Kalinowski <tomasz@posit.co>",
+      "Repository": "P3M"
+    },
     "zip": {
       "Package": "zip",
       "Version": "2.3.3",
diff --git a/tools/release-notes.R b/tools/release-notes.R
index 49b07ee4c7..57f363177a 100644
--- a/tools/release-notes.R
+++ b/tools/release-notes.R
@@ -3,6 +3,7 @@ library(stringr)
 library(glue)
 library(jsonlite)
 library(gh)
+library(yaml12)
 
 downloads <- path("docs", "download")
 
@@ -91,16 +92,39 @@ readLines(prerelease_page) |>
 
 old_abbr <- str_split(major_version, "\\.")[[1]] |> paste0(collapse = "")
 
-# Add new item to download-older listing in docs/download/index.qmd
+# Add or update item in download-older listing
+older_file <- path(downloads, "_download-older.yml")
+
+# Preserve comment header, parse YAML data
+file_lines <- readLines(older_file)
+comment_lines <- file_lines[startsWith(file_lines, "#")]
+yaml_text <- file_lines[!startsWith(file_lines, "#")]
+entries <- parse_yaml(paste(yaml_text, collapse = "\n"))
+
+new_entry <- list(
+  id = paste0("version", old_abbr),
+  title = old_release,
+  date = format(as.Date(old_release_date), "%Y-%m-%d"),
+  path = paste0("https://github.com/quarto-dev/quarto-cli/releases/tag/v", old_release),
+  changelog = paste0("[Release Notes](changelog/", major_version, "/)")
+)
+
+# Upsert: update existing entry or append new one
+existing_idx <- which(vapply(entries, function(e) identical(e$title, old_release), logical(1)))
+
+if (length(existing_idx) > 0) {
+  entries[[existing_idx[1]]] <- new_entry
+  cat("Updated version", old_release, "in _download-older.yml\n")
+} else {
+  entries <- c(entries, list(new_entry))
+  cat("Added version", old_release, "to _download-older.yml\n")
+}
 
-glue('
-\n- id: version{ old_abbr }
-  title: { old_release }
-  date: { format(as.Date(old_release_date), "%Y-%m-%d") }
-  path: https://github.com/quarto-dev/quarto-cli/releases/tag/v{ old_release }
-  changelog: "[Release Notes](changelog/{ major_version }/)"
-') |>
-  cat(file = path(downloads, "_download-older.yml"), append = TRUE)
+# Write back: comments + formatted YAML
+writeLines(
+  c(comment_lines, format_yaml(entries)),
+  older_file
+)
 
 # Update version for prerelease-docs-url shortcode -------------------------
 # _quarto.yml tracks the stable release version. Bumping it here on the