I was looking through the brochure for Australia's P-TECH styled model. I think this paragraph is important:
"Secondary students involved in the P-TECH pilot will be on a pathway to achieve two qualifications. Firstly, their Senior Secondary Certificate of Education, which will feature a STEM related vocational education component. P-TECH students will then extend their studies beyond secondary school to achieve a STEM related diploma, advanced diploma or associate degree."
So it seems that P-TECH students in Australia have the means once they finish school to pursue further education, but they don't actually come out with a "college" diploma.
So the Senior Secondary certificate of Education (SSCE) is what the VCE and VCAL are from my previous post. So SSCE's are awarded for completing grade 11 and 12. Schooling is compulsory until grade 10 so you would get an SSCE for going the "extra" mile.
"In Australia, schooling is compulsory up until Year 10 (approximately age 15-16). Students leaving school at this level usually go into apprenticeships or begin training for a trade. Years 11 and 12, the final two years of secondary school in Australia, are designed to prepare students for higher level entry into training programs or to enter university. (source)"
So it feels like P-TECH Australia plays to this idea that the last 2 years oh highschool are not mandatory.