diff --git a/Cargo.toml b/Cargo.toml
index b8ba452..17618cc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ serde-transcode = "1.1.1"
 
 # Data types we support
 # Should tend to be equal to the official list of data formats supported by serde: https://serde.rs/#data-formats
+#bson = "2.3"
 #ciborium = "0.2"
 serde_json = "1.0"
 serde-pickle = "1.0"
diff --git a/src/lib.rs b/src/lib.rs
index 4c6a776..2016e5a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,17 +23,23 @@ pub struct Opt {
 
 #[derive(Copy, Clone, Debug, ValueEnum)]
 pub enum Input {
+    //Bson,
+    //Cbor,
     Json,
     Pickle,
     Ron,
+    //Toml
     Yaml,
 }
 
 #[derive(Copy, Clone, Debug, ValueEnum)]
 pub enum Output {
+    //Bson,
+    //Cbor,
     Json,
     Pickle,
     Ron,
+    //Toml,
     Yaml,
 }
 
@@ -56,6 +62,14 @@ pub fn transcode(opt: Opt, input: &mut dyn Read, output: &mut dyn Write) {
 
 fn de(opt: &Opt, input: &mut dyn Read, output: &mut dyn Write) {
     match opt.input {
+        /*
+        Input::Bson => {
+            use bson::Deserializer;
+
+            let mut deserializer = bson::from_reader(input).unwrap(); // FIXME: need which type annotation?
+            ser(opt, &mut deserializer, output);
+        }
+        */
         Input::Json => {
             use serde_json::Deserializer;
 
@@ -66,6 +80,7 @@ fn de(opt: &Opt, input: &mut dyn Read, output: &mut dyn Write) {
         Input::Pickle => {
             use serde_pickle::Deserializer;
 
+            // NOTE: Apparently serde_pickle do not implement `Deserializer` on const?
             let mut deserializer = Deserializer::new(input, serde_pickle::DeOptions::new());
             ser(opt, &mut deserializer, output);
         }
@@ -93,6 +108,21 @@ where
     D: Deserializer<'de>,
 {
     match opt.output {
+        /*
+        Output::Bson => {
+            use bson::Serializer;
+
+            let options = bson::SerializerOptions::builder();
+            let options = if opt.pretty {
+                options.human_readable(true)
+            } else {
+                options.human_readable(false)
+            };
+
+            let serializer = Serializer::new_with_options(options.build()); // FIXME: why no way to tell the serializer were we want the output?
+            serde_transcode::transcode(deserializer, serializer).unwrap();
+        }
+        */
         Output::Json => {
             use serde_json::Serializer;