is it legal to install sabs approved flexible cables from a main DB to a sub DB.

in other words run a circuit directly from a new DB installed in a basement

via a 21 core sabs approved flexible cable

then disconnect the existing circuits in the sub DB on the first floor and join then directly to the 21 core flex cable straight to the dedicated socket outlets...which are wired in house wire.

how important are the numbers in the flexible cable?

this is not a trick question i am