Formating a chemical equation - Physical states

I study chemistry in an University and I have two professors that says opposing things. One says that the physical state must be subscribed (1 at the picture) and other that it must be written to the left side (2). Since both of them are posdocs and have way more experience in chemistry than me, I really don't know to whom I should list. i've tried to look for a recommendation in the IUPAC site, but I couldn't find anything about that. Someone could help me with a link from some organization (preferably an international one) that recommends about this topic?

They suggest to write the state of aggregation as they call it, just next to your symbol like $$\ce{Na(s)}$$, not as a subscript.