diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index f8df416971593..91eef647713db 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -298,7 +298,11 @@ impl From<PathBuf> for FileName {
 
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
 pub enum FileNameDisplayPreference {
+    /// Display the path after the application of rewrite rules provided via `--remap-path-prefix`.
+    /// This is appropriate for paths that get embedded into files produced by the compiler.
     Remapped,
+    /// Display the path before the application of rewrite rules provided via `--remap-path-prefix`.
+    /// This is appropriate for use in user-facing output (such as diagnostics).
     Local,
 }