Hello,
after I canceled the migration from SLES12 to SLES12 SP3 the registration has been removed, now I get:

SUSEConnect -r <code> -e <email>
Error: SCC returned 'The subscription with the provided Registration Code does not include the requested product 'SUSE Linux Enterprise Server 12 x86_64'' (422)

zypper pd -i gets:
S | Repository | Internal Name | Name | Version | Arch | Is Base
--+------------+-----------------------+---------------------------------------------------+---------+--------+--------
i | @System | SLES | SUSE Linux Enterprise Server 12 | 12-0 | x86_64 | Yes
i | @System | sgi-foundation | SGI Foundation Software 2.13 | 2.13-0 | x86_64 | No
i | @System | sle-module-containers | Containers module | 12-0 | x86_64 | No
i | @System | sle-sdk | SUSE Linux Enterprise Software Development Kit 12 | 12-0 | x86_64 | No

In https://scc.suse.com I see 4 subscriptions like:
SUSE Linux Enterprise High Performance Computing, x86-64, 1-2 Sockets, L3 Standard Subscription

Thank you for any solution,

Michal