bupa standard visitor cover的这个条款什么意思？

modao520

A waiting period is the time when you are not covered for a particular service. It starts on the date that you enter Australia or the date that you start your membership, whichever is the later date. Once you have completed your waiting period, you will receive the full benefits listed under your level of cover for that service. Di£erent waiting periods apply for di£erent services.

Pre-existing conditions, ailments, or illnesses 12 months
是不是说如果先前有病，要等12个月后保险才生效？如果12个月内发病，12个月后保险继续生效吗，还是自动取消了？
这个一直没搞懂，因为父母年纪都大了，肯定有各种病，那么这个保险岂不不能保在澳洲呆的12个月了？