Adding a little more doc describing that view access to the labelprop

of a class is required to display the elements of that class when
iterating over a multilink.

Author: rouilj

doc/FAQ.txt

@@ -172,6 +172,12 @@ There are examples in the devel and responsive templates. Search for
 LocalReplace to find the extension file and the change that has to be
 made to the item template.
 
+I can see values in a multilink but not display the items
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Make sure that you have allowed the user to view the labelprop for the
+multilink class. Look for the setlabelprop explanation in the Roundup
+customisation_ documentation.
 
 Using Roundup
 -------------

doc/customizing.txt

@@ -857,6 +857,11 @@ a class, the following values are tried for the label:
 So in most cases you can get away without specifying setlabelprop
 explicitly.
 
+You should make sure that users have View access to this property or
+the id property for a class. If the property can not be viewed by a
+user, looping over items in the class (e.g. messages attached to an
+issue) will not work.
+
 setorderprop(property)
 ~~~~~~~~~~~~~~~~~~~~~~