Players subject to international cap restrictions shall be considered prospects, and as such, ineligible to be taken in the Rule 5. They can be selected in the next rule 4. Or, if they somehow hit AA and hit Yahoo's database while they are still unowned, they are waiver claim bait.
Players who are older and aren't subject to international cap restrictions can be taken in the Rule 5. (Ryu, Tanaka, Abreu, Adelmyis Diaz, Alex Guerrero, Miguel Alfredo sauce whatever, etc.)
If these weren't already common sense, then they are new rules.
I think that covers all the bases. Only point of question might be players who sign big league deals despite being subject to international cap restrictions. We could just say that all big league deals by an international make them rule 5 eligible regardless of age.