When creating a field in a table, one may set a Lookup using a Value List. Clicking in the Row Source line will then display an ellipsis which, if clicked, will bring up the Value List Editor. So far, so good.
If one then changes the line "Allow Value List Edits" from "Yes" to "No", the user will then not be able to edit the list of values when doing non-structural things like adding or editing -data- (which is the expected behavior).
However, in Access 2013, setting that line from "Yes" to "No" -also- prevents the Value List Editor from appearing (no ellipsis!) while working in the structure. In other words: One must manually enter the values in the Row Source line
or toggle the setting from "No" to "Yes" and then remember to toggle it back before exiting the structure mode.
In earlier versions of Access, this was not the behavior. The Value List Editor was and should -always- be available when working in the structure regardless of the setting of "Allow Value List Edits".