CITROËN DS 5 Handbook page 174

"RÖMER duo Plus ISOFIX"
(size category B1)
Group 1: from 9 to 18 kg
Installed only in the forward facing position.
Attached to the rings A, as well as the ring B, referred to as the TOP TETHER,
using an upper strap.
Three seat body angles: sitting, reclining, lying.
This child seat can also be used on seats which are not fitted with ISOFIX mountings. In this case,
it must be attached to the vehicle seat using the three point seat belt.
Baby P2c Midi and its ISOFIX base
(size categories: d, c, A, B, B1)
Group 1: from 9 to 18 kg
Installed rearward facing using an ISOFIX base which is attached to the rings A.
The base includes a support leg, adjustable for height, which rests on the vehicle's floor.
This child seat can also be used forward facing.
This child seat can not be secured with a seat belt.
We recommend that it be used rearward facing up to 3 years.