diff --git a/src/possum/did.gleam b/src/possum/did.gleam
index 548175b..b5e906e 100644
--- a/src/possum/did.gleam
+++ b/src/possum/did.gleam
@@ -14,7 +14,8 @@ import gleam/regexp
 import gleam/result
 import gleam/string
 
-pub const pattern = "^did:[a-z]+:[a-zA-Z0-9._:%-]*[a-zA-Z0-9._-]$"
+/// Available on: https://atproto.com/specs/did#did-identifier-syntax
+const pattern = "^did:[a-z]+:[a-zA-Z0-9._:%-]*[a-zA-Z0-9._-]$"
 
 pub type ParseError {
   /// Regex failed to compile