  Given a structure $M$ we introduce infinitary logic expansions, which
generalise the Morleyisation. We show that these expansions are tame, in the
sense that they preserve and reflect both the Embedding Ramsey Property (ERP)
and the Modelling Property (MP). We then turn our attention to Scow's theorem
connecting generalised indiscernibles with Ramsey classes and show that by
passing through infinitary logic, one can obtain a stronger result, which does
not require any technical assumptions. We also show that every structure with
ERP, not necessarily countable, admits a linear order which is a union of
quantifier-free types, effectively proving that any Ramsey structure is
``essentially'' ordered. We also introduce a version of ERP for classes of
structures which are not necessarily finite (the finitary-ERP) and prove a
strengthening of the Kechris-Pestov-Todorcevic correspondence for this notion.
