McLaren has made reference to its power unit reunion with Mercedes by naming its 2021 car the MCL35M.
McLaren is the only team to change power units from last year to this, switching from Renault to Mercedes, and has used all of its development tokens for the year to accommodate the change.
A spokesperson for the team confirmed to GPFans Global the 'M' "denotes the Mercedes power unit addition".
McLaren and Mercedes previously partnered between 1995-2014, securing the 1998 constructors' title and three drivers' crowns - '98 and '99 with Mika Hakkinen and 2008 with Lewis Hamilton.
Last year, McLaren finished third in the constructors' championship, its highest position since 2012, after coming out on top in a fierce, season-long battle with Racing Point and Renault.
With Mercedes power and a new driver partnership of Daniel Ricciardo, who joins from Renault, and Lando Norris, McLaren will aim to at least retain its position at the head of the midfield.
In terms of car name, McLaren last broke from its numerical order in 2004 when the MP4-19 was replaced with the MP4-19B midway through the season due to the team suffering a series of reliability issues.
With a large carryover of parts from last season to this, McLaren has followed the example of Red Bull in labelling the 'new' machinery as a 'B-spec' car, with the Milton Keynes-based marque naming this season's challenger the RB16B as opposed to the RB17.