It is common in machine learning papers to see notation such as
$$X \in \mathcal{X}$$
where both variables are "X" but one is in calligraphy (\mathcal in typesetting). When reading a document using such notation, the difference between variables is obvious, but orally "X in X" may be confusing to some listeners.
Is there a standard (or even common) parlance/notation used to refer to calligraphic letters orally?