minor #6923 Clarify by_reference use (jxmallett)

This PR was submitted for the 3.1 branch but it was merged into the 2.7 branch instead (closes #6923).

Discussion
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Clarify by_reference use

I'd like to make it clear that `by_reference` must be set to `false` if the developer requires that an entity's setter method be called.

Commits
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6675692 Clarify by_reference use

Author: xabbuh

reference/forms/types/options/by_reference.rst.inc

@@ -3,9 +3,9 @@ by_reference
 
 **type**: ``boolean`` **default**: ``true``
 
-In most cases, if you have a ``name`` field, then you expect ``setName()``
-to be called on the underlying object. In some cases, however, ``setName()``
-may *not* be called. Setting ``by_reference`` ensures that the setter is
+In most cases, if you have an ``author`` field, then you expect ``setAuthor()``
+to be called on the underlying object. In some cases, however, ``setAuthor()``
+may *not* be called. Setting ``by_reference`` to ``false`` ensures that the setter is
 called in all cases.
 
 To explain this further, here's a simple example::