From da750a74fc91d26ba39205201a33ac1d6b5b49fb Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 20 Oct 2021 15:24:27 +0900
Subject: [PATCH] Add xmldoc mention of valid `OnlineID` values

---
 osu.Game/Database/IHasOnlineID.cs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Database/IHasOnlineID.cs b/osu.Game/Database/IHasOnlineID.cs
index 529c68a8f8..6e2be7e1f9 100644
--- a/osu.Game/Database/IHasOnlineID.cs
+++ b/osu.Game/Database/IHasOnlineID.cs
@@ -8,8 +8,12 @@ namespace osu.Game.Database
     public interface IHasOnlineID
     {
         /// <summary>
-        /// The server-side ID representing this instance, if one exists. -1 denotes a missing ID.
+        /// The server-side ID representing this instance, if one exists. Any value 0 or less denotes a missing ID.
         /// </summary>
+        /// <remarks>
+        /// Generally we use -1 when specifying "missing" in code, but values of 0 are also considered missing as the online source
+        /// is generally a MySQL autoincrement value, which can never be 0.
+        /// </remarks>
         int OnlineID { get; }
     }
 }