# Article 12 — Reporting of an execution for a combination of financial instruments **Commission Delegated Regulation (EU) 2017/590 · binding · OJ L 87, 31.3.2017 · dated 28 Jul 2016 [in force]** *In force · Commission Delegated Regulation (EU) 2017/590, OJ L 87, 31.3.2017 · Checked against EUR-Lex on 26 Oct 2026 · [Official source](https://eur-lex.europa.eu/eli/reg_del/2017/590/oj/eng)* Where an investment firm executes a transaction involving two or more financial instruments, the investment firm shall report the transaction for each financial instrument separately and shall link those reports by an identifier that is unique at the level of the firm to the group of transaction reports related to that execution as specified in field 40 of Table 2 of Annex I.