diff --git a/index.html b/index.html
index 9912771..f93ffcd 100644
--- a/index.html
+++ b/index.html
@@ -91,12 +91,21 @@
     max-width: 16em;
   }
 
-  .proposed-type {
+  .option-proposed {
     font-size: 1em;
   }
-  .well-known-type {
+  .option-well-known {
     font-size: 2em;
   }
+
+  .identifier-well-known {
+    text-decoration: underline #007700 0.2em;
+    background-color: #bbffbb;
+  }
+  .identifier-proposed {
+    text-decoration: underline #777700 0.2em;
+    background-color: #ffffbb;
+  }
   </style>
 
 </head>
diff --git a/src/main.rs b/src/main.rs
index 5fd5232..0daf6aa 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -52,8 +52,8 @@ fn MainContent() -> impl IntoView {
             }>
                 {
                     purl_data::PURL_TYPES.iter()
-                        .map(|(type_option, choice_well_known)| view! {
-                            <PurlTypeOption typestr is=type_option well_known=*choice_well_known/>
+                        .map(|(type_option, choice_status)| view! {
+                            <PurlTypeOption typestr is=type_option status=*choice_status/>
                         })
                         .collect_view()
                  }
@@ -112,14 +112,14 @@ fn MainContent() -> impl IntoView {
 pub fn PurlTypeOption(
     is: &'static str,
     typestr: ReadSignal<String>,
-    well_known: bool,
+    status: purl_data::PurlTypeStatus,
 ) -> impl IntoView {
     view! {
         <option
-            class={ if well_known {
-                "well-known-type"
-            } else {
-                "proposed-type"
+            class={ match status {
+                purl_data::PurlTypeStatus::WellKnown => "option-well-known",
+                purl_data::PurlTypeStatus::Proposed => "option-proposed",
+                purl_data::PurlTypeStatus::Other => "option-other", // this case would not happen, normally
             }}
             value=is
             selected=move || typestr() == is
@@ -143,7 +143,11 @@ fn Purl(
         <div class="purl">
             <span class="purl-scheme">"pkg"</span>
             <span class="purl-sep">:</span>
-            <span class="purl-type">{typestr}</span>
+            <span class={ move || format!("{t} {status}", t="purl-type", status=match purl_data::get_purl_type_status(&typestr.get()) {
+                purl_data::PurlTypeStatus::WellKnown => "identifier-well-known",
+                purl_data::PurlTypeStatus::Proposed => "identifier-proposed",
+                purl_data::PurlTypeStatus::Other => "identifier-other",
+            })}>{typestr}</span>
             <span class="purl-sep">/</span>
             <span class="purl-namespace">{namespace}</span>
             <span class="purl-sep">/</span>
diff --git a/src/purl_data.rs b/src/purl_data.rs
index 216e6ad..a2da1e5 100644
--- a/src/purl_data.rs
+++ b/src/purl_data.rs
@@ -1,81 +1,95 @@
-pub const PURL_TYPES: &[(&str, bool)] = &[
-    ("alpm", true),
-    ("android", false),
-    ("apache", false),
-    ("apk", true),
-    ("atom", false),
-    ("bitbucket", true),
-    ("bitnami", true),
-    ("bower", false),
-    ("brew", false),
-    ("buildroot", false),
-    ("cargo", true),
-    ("carthage", false),
-    ("chef", false),
-    ("chocolatey", false),
-    ("clojars", false),
-    ("cocoapods", true),
-    ("composer", true),
-    ("conan", true),
-    ("conda", true),
-    ("coreos", false),
-    ("cpan", false),
-    ("cran", true),
-    ("crystal", false),
-    ("ctan", false),
-    ("deb", true),
-    ("docker", true),
-    ("drupal", false),
-    ("dtype", false),
-    ("dub", false),
-    ("ebuild", false),
-    ("eclipse", false),
-    ("elm", false),
-    ("gem", true),
-    ("generic", true),
-    ("gitea", false),
-    ("github", true),
-    ("gitlab", false),
-    ("golang", true),
-    ("gradle", false),
-    ("guix", false),
-    ("hackage", true),
-    ("haxe", false),
-    ("helm", false),
-    ("hex", true),
-    ("huggingface", true),
-    ("julia", false),
-    ("lua", false),
-    ("maven", true),
-    ("melpa", false),
-    ("meteor", false),
-    ("mlflow", true),
-    ("nim", false),
-    ("nix", false),
-    ("npm", true),
-    ("nuget", true),
-    ("oci", true),
-    ("opam", false),
-    ("openwrt", false),
-    ("osgi", false),
-    ("p2", false),
-    ("pear", false),
-    ("pecl", false),
-    ("perl6", false),
-    ("platformio", false),
-    ("pub", true),
-    ("puppet", false),
-    ("pypi", true),
-    ("qpkg", true),
-    ("rpm", true),
-    ("sourceforge", false),
-    ("sublime", false),
-    ("swid", true),
-    ("swift", true),
-    ("terraform", false),
-    ("vagrant", false),
-    ("vim", false),
-    ("wordpress", false),
-    ("yocto", false),
+pub const PURL_TYPES: &[(&str, PurlTypeStatus)] = &[
+    ("alpm", PurlTypeStatus::WellKnown),
+    ("android", PurlTypeStatus::Proposed),
+    ("apache", PurlTypeStatus::Proposed),
+    ("apk", PurlTypeStatus::WellKnown),
+    ("atom", PurlTypeStatus::Proposed),
+    ("bitbucket", PurlTypeStatus::WellKnown),
+    ("bitnami", PurlTypeStatus::WellKnown),
+    ("bower", PurlTypeStatus::Proposed),
+    ("brew", PurlTypeStatus::Proposed),
+    ("buildroot", PurlTypeStatus::Proposed),
+    ("cargo", PurlTypeStatus::WellKnown),
+    ("carthage", PurlTypeStatus::Proposed),
+    ("chef", PurlTypeStatus::Proposed),
+    ("chocolatey", PurlTypeStatus::Proposed),
+    ("clojars", PurlTypeStatus::Proposed),
+    ("cocoapods", PurlTypeStatus::WellKnown),
+    ("composer", PurlTypeStatus::WellKnown),
+    ("conan", PurlTypeStatus::WellKnown),
+    ("conda", PurlTypeStatus::WellKnown),
+    ("coreos", PurlTypeStatus::Proposed),
+    ("cpan", PurlTypeStatus::Proposed),
+    ("cran", PurlTypeStatus::WellKnown),
+    ("crystal", PurlTypeStatus::Proposed),
+    ("ctan", PurlTypeStatus::Proposed),
+    ("deb", PurlTypeStatus::WellKnown),
+    ("docker", PurlTypeStatus::WellKnown),
+    ("drupal", PurlTypeStatus::Proposed),
+    ("dtype", PurlTypeStatus::Proposed),
+    ("dub", PurlTypeStatus::Proposed),
+    ("ebuild", PurlTypeStatus::Proposed),
+    ("eclipse", PurlTypeStatus::Proposed),
+    ("elm", PurlTypeStatus::Proposed),
+    ("gem", PurlTypeStatus::WellKnown),
+    ("generic", PurlTypeStatus::WellKnown),
+    ("gitea", PurlTypeStatus::Proposed),
+    ("github", PurlTypeStatus::WellKnown),
+    ("gitlab", PurlTypeStatus::Proposed),
+    ("golang", PurlTypeStatus::WellKnown),
+    ("gradle", PurlTypeStatus::Proposed),
+    ("guix", PurlTypeStatus::Proposed),
+    ("hackage", PurlTypeStatus::WellKnown),
+    ("haxe", PurlTypeStatus::Proposed),
+    ("helm", PurlTypeStatus::Proposed),
+    ("hex", PurlTypeStatus::WellKnown),
+    ("huggingface", PurlTypeStatus::WellKnown),
+    ("julia", PurlTypeStatus::Proposed),
+    ("lua", PurlTypeStatus::Proposed),
+    ("maven", PurlTypeStatus::WellKnown),
+    ("melpa", PurlTypeStatus::Proposed),
+    ("meteor", PurlTypeStatus::Proposed),
+    ("mlflow", PurlTypeStatus::WellKnown),
+    ("nim", PurlTypeStatus::Proposed),
+    ("nix", PurlTypeStatus::Proposed),
+    ("npm", PurlTypeStatus::WellKnown),
+    ("nuget", PurlTypeStatus::WellKnown),
+    ("oci", PurlTypeStatus::WellKnown),
+    ("opam", PurlTypeStatus::Proposed),
+    ("openwrt", PurlTypeStatus::Proposed),
+    ("osgi", PurlTypeStatus::Proposed),
+    ("p2", PurlTypeStatus::Proposed),
+    ("pear", PurlTypeStatus::Proposed),
+    ("pecl", PurlTypeStatus::Proposed),
+    ("perl6", PurlTypeStatus::Proposed),
+    ("platformio", PurlTypeStatus::Proposed),
+    ("pub", PurlTypeStatus::WellKnown),
+    ("puppet", PurlTypeStatus::Proposed),
+    ("pypi", PurlTypeStatus::WellKnown),
+    ("qpkg", PurlTypeStatus::WellKnown),
+    ("rpm", PurlTypeStatus::WellKnown),
+    ("sourceforge", PurlTypeStatus::Proposed),
+    ("sublime", PurlTypeStatus::Proposed),
+    ("swid", PurlTypeStatus::WellKnown),
+    ("swift", PurlTypeStatus::WellKnown),
+    ("terraform", PurlTypeStatus::Proposed),
+    ("vagrant", PurlTypeStatus::Proposed),
+    ("vim", PurlTypeStatus::Proposed),
+    ("wordpress", PurlTypeStatus::Proposed),
+    ("yocto", PurlTypeStatus::Proposed),
 ];
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum PurlTypeStatus {
+    WellKnown,
+    Proposed,
+    Other,
+}
+
+pub fn get_purl_type_status(typestr: &str) -> PurlTypeStatus {
+    if let Some(found) = PURL_TYPES.iter().find(|(t, _)| *t == typestr) {
+        found.1
+    } else {
+        PurlTypeStatus::Other
+    }
+}