Red Bull is definitely appealing Daniel Ricciardo's disqualification from the Australian grand prix.
Immediately after the Melbourne stewards' verdict was published, boss Christian Horner said the team would file an appeal.
An FIA source said on Monday that Red Bull served notice of its intention to appeal, but formal documentation was not due to be lodged for four days.
Those papers were indeed lodged on the fourth day, Thursday, media agencies Reuters, the Associated Press and Press Association reported.
F1's official website, and a spokesperson for the reigning world champions, confirmed the news.