How the 16 templates fit together
The return is built in three layers. The organisational layer — Z 01.01 and Z 01.02 — establishes which legal entities exist and who owns whom; every other template identifies entities by the code reported there. The aggregate layer — Z 02.00 to Z 06.00 — describes the balance sheet in buckets defined by resolution treatment rather than by accounting category. The granular layer — Z 11.00 to Z 17.00 — describes the same liabilities one transaction or one instrument at a time, and each of its rows carries an explicit reconciliation back to a row and a column of Z 02.00.
This is what allows an authority to move between two views of the same balance sheet: the aggregate view it uses to calibrate MREL, and the instrument-level view it would need to actually execute a bail-in.
What differs by entity
Reporting requirements are differentiated: a resolution entity, an entity earmarked for liquidation and another member of a resolution group do not file the same content, and thresholds decide which subsidiaries are relevant legal entities reported individually. The flag that carries this through the return is column 0320 of Z 01.01. Institutions under simplified obligations report a reduced set on the terms their authority sets.