diff --git a/repository/main.go b/repository/main.go
index 591b384..4ebe050 100644
--- a/repository/main.go
+++ b/repository/main.go
@@ -131,11 +131,21 @@ var Main = Packages{
 		}, {
 			Comment: Comment{`
 				Imager implies the segment should be replaced with a (possibly
-				inlined) image. Unless the Imager segment covers something
-				meaningful, only the starting bound should matter, as images
-				must not substitute texts and only complement them. An example
-				of this would be having Imager cover the entire chunk that
-				Mentioner does.
+				inlined) image.
+
+				The Imager segment must return a bound of length zero, that is,
+				the start and end bounds must be the same, unless the Imager
+				segment covers something meaningful, as images must not
+				substitute texts and only complement them.
+
+				An example of the start and end bounds being the same would be
+				any inline image, and an Imager that belongs to a Mentioner
+				segment should have its bounds overlap. Normally,
+				implementations with separated Mentioner and Imager
+				implementations don't have to bother about this, since with
+				Mentioner, the same Bounds will be shared, and with Imager, the
+				Bounds method can easily return the same variable for start and
+				end.
 
 				For segments that also implement mentioner, the image should be
 				treated as a square avatar.
diff --git a/text/text.go b/text/text.go
index c58f376..213d373 100644
--- a/text/text.go
+++ b/text/text.go
@@ -93,10 +93,18 @@ type Colorer interface {
 }
 
 // Imager implies the segment should be replaced with a (possibly inlined)
-// image. Unless the Imager segment covers something meaningful, only the
-// starting bound should matter, as images must not substitute texts and only
-// complement them. An example of this would be having Imager cover the entire
-// chunk that Mentioner does.
+// image.
+//
+// The Imager segment must return a bound of length zero, that is, the start and
+// end bounds must be the same, unless the Imager segment covers something
+// meaningful, as images must not substitute texts and only complement them.
+//
+// An example of the start and end bounds being the same would be any inline
+// image, and an Imager that belongs to a Mentioner segment should have its
+// bounds overlap. Normally, implementations with separated Mentioner and Imager
+// implementations don't have to bother about this, since with Mentioner, the
+// same Bounds will be shared, and with Imager, the Bounds method can easily
+// return the same variable for start and end.
 //
 // For segments that also implement mentioner, the image should be treated as a
 // square avatar.