Are there some qualifications that cannot be assessed?

Yes. The following courses aren’t assessed by QTAC:
Australian Qualifications Framework (AQF) Certificates I and II
Statements of Attainment
TAFE Statements
Courses delivered by Australian private providers that are not accredited. Only those courses accredited under the Australian Qualifications Framework, or by the relevant state/territory accreditation authority, will be taken into account. Qualifications undertaken with private providers will not be assessed without proof of accreditation for the particular course
Short courses run by a university (e.g. Project Management Essentials)
Other short courses such as First Aid certificates.
If you have undertaken any of these qualifications, you don’t need to include them in your application.