Original: They are signed with Warp Records and have released several works on that label with little advertising and few interviews, while also having an elusive and obscure back-catalogue of releases on their self-run Music70 label.
Simplified: They are signed with Warp Records and have released several works on that label with little advertising and few interviews, while also having a secret, privately-released back-catalogue of albums on their self-run Music70 label.