diff --git a/src/config.rs b/src/config.rs
index 8b7a2b6..98da773 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -24,6 +24,7 @@ lazy_static! {
     pub static ref LOC: Value = init_lang();
 }
 
+// Open LOC_FILE and store it in memory (LOC)
 fn init_lang() -> Value {
     let mut file = File::open(LOC_FILE).expect("init_lang: Can't open translations file");
     let mut data = String::new();
@@ -32,6 +33,7 @@ fn init_lang() -> Value {
     serde_json::from_str(&data).expect("init_lang(): Can't parse translations file")
 }
 
+// Open a file from its path
 fn lines_from_file(filename: impl AsRef<Path>) -> io::Result<Vec<String>> {
     BufReader::new(File::open(filename)?).lines().collect()
 }
@@ -52,6 +54,7 @@ pub struct Config {
 
 // totally not copypasted from rs-short
 impl Config {
+    // open and parse CONFIG_FILE
     pub fn init() -> Self {
         let mut conffile = File::open(CONFIG_FILE).expect(
             r#"Config file config.toml not found.
@@ -63,6 +66,9 @@ impl Config {
             .expect("Couldn't read config to string");
         toml::from_str(&confstr).expect("Couldn't deserialize the config")
     }
+
+    // if config.config_version doesn't match the hardcoded version,
+    // ask the admin to manually upgrade its config file
     pub fn check_version(&self) {
         if self.config_version != CONFIG_VERSION {
             eprintln!("Your configuration file is obsolete!\nPlease update it following the instructions in https://git.42l.fr/neil/sncf/wiki/Upgrade-from-a-previous-version and update its version to {}.", CONFIG_VERSION);