diff --git a/Limit.hs b/Limit.hs
index 483336eb9f..5d00e2e688 100644
--- a/Limit.hs
+++ b/Limit.hs
@@ -163,6 +163,8 @@ addCopies = addLimit . limitCopies
 
 limitCopies :: MkLimit Annex
 limitCopies want = case splitc ':' want of
+	-- Note that in case of a group having the same name as a trust
+	-- level, it's parsed as a trust level, not as a group.
 	[v, n] -> case parsetrustspec v of
 		Just checker -> go n $ checktrust checker
 		Nothing -> go n $ checkgroup v
diff --git a/doc/bugs/Missing_sanity_check_of_group_names._Special_group_names_should_not_be_allowed./comment_1_b4ba41b6e0e611d90ddda92bbe991266._comment b/doc/bugs/Missing_sanity_check_of_group_names._Special_group_names_should_not_be_allowed./comment_1_b4ba41b6e0e611d90ddda92bbe991266._comment
new file mode 100644
index 0000000000..4bd9247927
--- /dev/null
+++ b/doc/bugs/Missing_sanity_check_of_group_names._Special_group_names_should_not_be_allowed./comment_1_b4ba41b6e0e611d90ddda92bbe991266._comment
@@ -0,0 +1,22 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 1"""
+ date="2018-06-04T16:06:57Z"
+ content="""
+Thanks for pointing out this ambiguity, which I don't remember having
+ever considered.
+
+The code for this does look for the name of a trust level first,
+and only a group name if it's not a trust level. So, adding a group
+with a colliding name will never change the behavior of such a command
+or preferred content expression.
+
+The only problem then would be that you couldn't match
+on a group by that name. But if you run into that problem,
+you can simply rename your group.
+
+So I don't think that git-annex needs a sanity check, really.
+
+(I have added a comment in the code to make clear that the order of
+parsing this does matter.)
+"""]]