Unidentified reserve fleet

"It won't take long before the Separatists take Anaxes, compromising our entire reserve fleet."

- Mace Windu, to Anakin Skywalker

During the Clone Wars between the Galactic Republic and the Separatist Alliance, a reserve fleet was part of the Republic Navy by the time of the Battle for Anaxes. During the battle, the Separatists overran the main shipyard production facility, which risked that the Republic would lose the planet. If that happened, the entirety of this reserve fleet would be compromised.

Behind the scenes
This reserve fleet was first mentioned, albeit unnamed, in the first episode of the seventh and final season of Star Wars: The Clone Wars in 2020, although the episode was originally part of The Clone Wars Legacy and released online in 2015 although at that time is was not fully rendered and was still in development.