Is it okay to shortcut names in the exam for eg. disc. rev. , accum. depn - vehicle, etc?
I'd say
Acc. Dep'n of [NCA] is the only abbreviation VCAA would accept. They have used it numerous times in their Assessment Reports over the years. However, they write the full 'Accumulated Depreciation - NCA' in the Balance Sheet, this is because there is always enough space to do so.
If you're short on time, the only place I'd write the abbreviation would be in the 'Disposal of NCA' General Ledger account, due to the lack of space. In saying that, if you have the time up your sleeve, take the extra 5 seconds out to try and fit it into the cross reference column, you never know what assessor you'll get (as stated in a previous post).