The FIA has told teams that they are allowed to mount mirrors directly to the halo instead of the cockpit if they so choose.
Increased effort has gone into the design of mirrors for 2018, with Ferrari in particular sculpting the housing to better manage airflow.
The sport's technical department has written to teams explaining that it was happy for teams to use the halo to mount the mirrors, provided they were sufficiently stable.
An imaginary box surrounds where teams can fit mirrors, which must be no smaller than 150mm x 50mm.
If fitted to the halo, the mirrors would still need to fall within the same location.
However, teams cannot mount the mirrors to both the halo and the top of the cockpit, with the FIA ruling this could make removing the halo in the event of an incident more difficult.
The FIA also pointed out that, should mirrors be attached to the halo, they could not include any cameras as it would change the integrity of the halo.
Currently, at the request of Formula One Management, teams do sport cameras in their mirrors from time to time.
“We will not accept a cable or connectors to run through the halo fairing, hence in the rare case when a team is asked to mount cameras in the mirrors (position 1 of Drawing 6 of the Technical Regulations), that team would have to resort in using a mirror installation on the chassis or side pod.”
It is currently not known if any teams intend to mount their mirrors on the halo.