[Question]: Does the `default_cdisc_join_keys` contain exhaustive list of CDISC datasets?

### What is your question?

When testing about `default_cdisc_join_keys` along with the `scda` datasets. I was unable to find the join keys for ` c("ADAB" "ADPC" "ADPP" "ADTR")` in the `default_cdisc_join_keys` however they were present in `scda`. There were also additional join keys in the `default_cdisc_join_keys` `c("ADSAFTTE" "ADCSSRS" "ADEQ5D5L")` which were missing in the `scda` datasets.

I thought that CDISC datasets formats contain an exhaustive list of datasets (at least for a given version of the SDTM). My question is do we need to extend the `default_cdisc_join_keys` to include the missing datasets from `scda`? Perhaps also add all the available datasets in the `default_cdisc_join_keys` into `scda`.

```r
join_key_datasets <- default_cdisc_join_keys |> names()
latest_scda_names <- scda::synthetic_cdisc_data("latest") |> names() |> toupper()

setdiff(latest_scda_names, join_key_datasets)
# [1] "ADAB" "ADPC" "ADPP" "ADTR"
setdiff(join_key_datasets, latest_scda_names)
# [1] "ADSAFTTE" "ADCSSRS" "ADEQ5D5L"
```

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