EMIR have today released a new version of their questions and answers document.

Only one answer would appear to have been updated, that relating to the use of Legal Entity Identifiers (LEIs).

the answer is found on page 45 of the document, and says the following:

Q: What code should be used to identify counterparties (LEIs, interim LEIs or BICs)?

A: A pre-LEI issued by any of the endorsed pre-LOUs (Local Operating Units) of the Global Legal Entity Identifier System. The list of endorsed pre-LOUs is available here.

ESMA are in effect endorsing these pre LEI sources and mandating the codes found within them for use in Trade Reporting. If nothing else, this provides a bit of clarity over how to deal with the LEI issue for trade reporting.