  Effective communication requires the ability to refer to specific parts of an
observation in relation to others. While emergent communication literature
shows success in developing various language properties, no research has shown
the emergence of such positional references. This paper demonstrates how agents
can communicate about spatial relationships within their observations. The
results indicate that agents can develop a language capable of expressing the
relationships between parts of their observation, achieving over 90% accuracy
when trained in a referential game which requires such communication. Using a
collocation measure, we demonstrate how the agents create such references. This
analysis suggests that agents use a mixture of non-compositional and
compositional messages to convey spatial relationships. We also show that the
emergent language is interpretable by humans. The translation accuracy is
tested by communicating with the receiver agent, where the receiver achieves
over 78% accuracy using parts of this lexicon, confirming that the
interpretation of the emergent language was successful.
