I might be wrong, as I do noz know what the purpose of this overview is, but to the best of my knowledge there are two types of codeshares here:
The longhaul ones such as SIN - FRA on LH / SIN - AKL on NZ and LHR - YYZ on AC.
These are genuine codeshares which can be booked anytime.
The shorthaul codeshare such as the ones on BM or the Intra German / European codeshares on LH can only be booked in conjunction with a longhaulfeed on SQ or the above longhaul SQ codeshares. It is not possible to book them independant / solely. There is some speical check when trying to book them - have tried it with my TA - thinking that FRA-ARN would be nice to collect sectors

as I do take this return trip at least once a month but it does not work.
Would be happy to be proven wrong though
Cheers
Thomas