diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 671ca25f..c82907ca 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -48,7 +48,9 @@ use crate::renderer::source_map::{
 };
 use crate::renderer::styled_buffer::StyledBuffer;
 use crate::snippet::Id;
-use crate::{Annotation, AnnotationKind, Element, Group, Message, Origin, Patch, Snippet, Title};
+use crate::{
+    Annotation, AnnotationKind, Element, Group, Message, Origin, Patch, Report, Snippet, Title,
+};
 pub use anstyle::*;
 use margin::Margin;
 use std::borrow::Cow;
@@ -225,7 +227,7 @@ impl Renderer {
 
 impl Renderer {
     /// Render a diagnostic, a series of [`Group`]s
-    pub fn render(&self, groups: &[Group<'_>]) -> String {
+    pub fn render(&self, groups: Report<'_>) -> String {
         if self.short_message {
             self.render_short_message(groups).unwrap()
         } else {
diff --git a/src/snippet.rs b/src/snippet.rs
index 8ce857f7..9bb44020 100644
--- a/src/snippet.rs
+++ b/src/snippet.rs
@@ -11,6 +11,13 @@ pub(crate) const INFO_TXT: &str = "info";
 pub(crate) const NOTE_TXT: &str = "note";
 pub(crate) const WARNING_TXT: &str = "warning";
 
+/// A [diagnostic message][Title] and any associated context to help users
+/// understand it
+///
+/// The first [`Group`] is the "primary" group, ie it contains the diagnostic
+/// message. All subsequent [`Group`]s are for distinct pieces of context.
+pub type Report<'a> = &'a [Group<'a>];
+
 #[derive(Clone, Debug, Default)]
 pub(crate) struct Id<'a> {
     pub(crate) id: Option<Cow<'a, str>>,